1ground 
/ˈgraʊnd/ noun
plural grounds /ˈgraʊnd/ noun 1 the ground : the surface of the earth
▪ An apple fell to the ground. ▪ Mechanical problems kept the plane on the ground. ▪ They were lying/sitting on the ground. ▪ close to the ground = low to the ground ▪ The flight was watched by many observers on the ground. ▪ They sent in ground forces/troops. [=soldiers who fight on the ground instead of in the air or at sea] ▪ a ground war [=a war fought by soldiers on the ground] ▪ ground transportation [=transportation that is over the ground instead of on water or in the air] 2 [noncount] : the soil that is on or under the surface of the earth
▪ planting seeds in the ground ▪ She drove a spike into the ground. ▪ damp/frozen ground ▪ solid/firm/dry ground 3 a [noncount] : an area of land
▪ They built their house on bare/level/flat ground. ▪ We realized that we were on hallowed/sacred ground. ▪ They built their house on high ground.
b [count] : an area of land or sea that is used for a particular purpose
▪ a camping ground ▪ fishing/hunting grounds ▪ Each fall the birds return to their wintering grounds. ▪ (Brit) a football ground [=(US) a soccer field] ▪ an ancient burial ground [=a place where people were buried in ancient times] — see also spawning ground
c grounds [plural] : the land around a building
▪ the capitol grounds ▪ He was trespassing on school grounds. ▪ We toured the grounds of the estate. 4 [noncount] : the bottom of the ocean, a lake, etc.
▪ The boat struck ground. 5 [noncount] : an area of knowledge or interest
▪ We have a lot of ground to go over before the test. ▪ We covered much more ground [=we went over more information] than we expected to at the meeting. ▪ The book covers familiar ground. [=subjects that have often been discussed before] 6 [singular] : a place or situation in which someone or something is developed or tested
▪ The laboratory has become a testing ground for ideas about the origins of the universe. ▪ The tournament has come to be regarded as a proving ground for young players. 7 : a set of beliefs, opinions, or attitudes [noncount] ▪ The two sides are trying to find some common ground [=an area in which they can agree with each other] on these issues. ▪ When a politician talks about raising taxes, he's on dangerous ground. [=he is doing or saying something that may cause anger or criticism] [singular] ▪ The two sides continue to look for a middle ground [=a middle position] between two extremes. — see also high ground 8 [count] : a reason for doing or thinking something — usually plural ▪ The company has been accused of discriminating on the grounds of race. ▪ We have no grounds for believing that the crisis will end soon. ▪ Her husband's infidelity was grounds for divorce. ▪ Many critics have objected to the proposal on the grounds that [=because] it would be too costly. ▪ The law was rejected on the grounds that it was not constitutional. = The law was rejected on constitutional grounds. 9 grounds [plural] : very small pieces of crushed coffee beans
▪ coffee grounds 10 [count] US : a wire or metal object that makes an electrical connection with the earth — usually singular ▪ This metal bracket provides the ground. —called also (Brit) earth 11 [count] : the area behind or around a design
▪ The wallpaper has red tulips on a white ground. [=background]
▪ An apple fell to the ground. ▪ Mechanical problems kept the plane on the ground. ▪ They were lying/sitting on the ground. ▪ close to the ground = low to the ground ▪ The flight was watched by many observers on the ground. ▪ They sent in ground forces/troops. [=soldiers who fight on the ground instead of in the air or at sea] ▪ a ground war [=a war fought by soldiers on the ground] ▪ ground transportation [=transportation that is over the ground instead of on water or in the air]
▪ planting seeds in the ground ▪ She drove a spike into the ground. ▪ damp/frozen ground ▪ solid/firm/dry ground
▪ They built their house on bare/level/flat ground. ▪ We realized that we were on hallowed/sacred ground. ▪ They built their house on high ground.
b [count] : an area of land or sea that is used for a particular purpose
▪ a camping ground ▪ fishing/hunting grounds ▪ Each fall the birds return to their wintering grounds. ▪ (Brit) a football ground [=(US) a soccer field] ▪ an ancient burial ground [=a place where people were buried in ancient times] — see also spawning ground
c grounds [plural] : the land around a building
▪ the capitol grounds ▪ He was trespassing on school grounds. ▪ We toured the grounds of the estate.
▪ The boat struck ground.
▪ We have a lot of ground to go over before the test. ▪ We covered much more ground [=we went over more information] than we expected to at the meeting. ▪ The book covers familiar ground. [=subjects that have often been discussed before]
▪ The laboratory has become a testing ground for ideas about the origins of the universe. ▪ The tournament has come to be regarded as a proving ground for young players.
▪ coffee grounds
▪ The wallpaper has red tulips on a white ground. [=background]
above ground
: on top of the earth's surface
▪ The bird's nest is located high above ground.
▪ The bird's nest is located high above ground.
below ground
: under the earth's surface
▪ The seeds should be planted a few inches below ground.
▪ The seeds should be planted a few inches below ground.
break ground 1 : to dig into the ground at the start of building something
▪ Workers broke ground on the new stadium last week. 2 or break new ground : to make new discoveries
▪ Critics say that the study does not break (any) new ground in the search for a cure for cancer.
▪ Workers broke ground on the new stadium last week.
▪ Critics say that the study does not break (any) new ground in the search for a cure for cancer.
burn to the ground — see 1burn
down to the ground
Brit, informal : completely or perfectly
▪ The job suits her down to the ground. [=suits her perfectly]
▪ The job suits her down to the ground. [=suits her perfectly]
from the ground up 1 : completely or thoroughly
▪ The car has been redesigned from the ground up. 2 : from a point at which nothing has been done : from the very beginning
▪ They built the resort from the ground up.
▪ The car has been redesigned from the ground up.
▪ They built the resort from the ground up.
gain ground or make up ground
: to move faster so that you come closer to someone or something that is in front of you
▪ She was trailing in the race, but she was beginning to gain ground (on the leaders). — often used figuratively ▪ Alternative forms of energy are quickly gaining ground. [=becoming more popular or successful] ▪ The company has been gaining ground on [=catching up with] its competitors. ▪ The campaign is trying to make up ground by advertising heavily in key states.
▪ She was trailing in the race, but she was beginning to gain ground (on the leaders). — often used figuratively ▪ Alternative forms of energy are quickly gaining ground. [=becoming more popular or successful] ▪ The company has been gaining ground on [=catching up with] its competitors. ▪ The campaign is trying to make up ground by advertising heavily in key states.
get off the ground 1 : to begin to operate or proceed in a successful way
▪ The project never really got off the ground. 2 get (something) off the ground : to cause (something) to begin to operate or proceed in successful way
▪ We're still trying to get this project off the ground.
▪ The project never really got off the ground.
▪ We're still trying to get this project off the ground.
give ground
: to move backward when you are being attacked : retreat
▪ The troops were forced to give ground. — often used figuratively ▪ The controversy has continued, and both sides are still refusing to give ground.
▪ The troops were forced to give ground. — often used figuratively ▪ The controversy has continued, and both sides are still refusing to give ground.
have/keep your feet on the ground — see 1foot
hit the ground running — see 1hit
hold/stand your ground
: to not change your position when you are being attacked : to not retreat
▪ The troops managed to hold their ground despite a fierce enemy attack. — often used figuratively ▪ The company has managed to hold its ground in the marketplace. ▪ The president has continued to stand his ground despite criticism.
▪ The troops managed to hold their ground despite a fierce enemy attack. — often used figuratively ▪ The company has managed to hold its ground in the marketplace. ▪ The president has continued to stand his ground despite criticism.
into the ground 1 : to the point of being very tired or exhausted
▪ She's been working/running/driving herself into the ground. 2 : to the point of complete failure or ruin
▪ He ran that company into the ground. [=he destroyed that company] ▪ She drove that old car into the ground. [=she drove it until it would not run anymore]
▪ She's been working/running/driving herself into the ground.
▪ He ran that company into the ground. [=he destroyed that company] ▪ She drove that old car into the ground. [=she drove it until it would not run anymore]
lose ground
: to move slower so that you are farther away from someone or something that is in front of you
▪ She was beginning to lose ground (to the leaders) in the race. — often used figuratively ▪ The political party lost ground [=became less popular or successful; did not do well] in the election. ▪ The company is losing ground to [=falling behind; not doing as well as] its competitors.
▪ She was beginning to lose ground (to the leaders) in the race. — often used figuratively ▪ The political party lost ground [=became less popular or successful; did not do well] in the election. ▪ The company is losing ground to [=falling behind; not doing as well as] its competitors.
