1 : large in size
▪ a big house/room/field ▪ a big glass of soda ▪ He is a big [=tall and heavy] man. ▪ She moved to a bigger city. ▪ the biggest city in the state ▪ The tent is big enough for 10 people. [=there is enough space in the tent for 10 people] ▪ A great big [=very large, huge] truck pulled up beside us. ▪ I can't understand her writing; she uses too many big words. [=long words that many people don't know the meaning of] — see also the big city at city 2 : large in number or amount
▪ He led a big group through the museum. ▪ She was earning big money [=a lot of money] as a lawyer. — see also big bucks 3 : involving or including many people, things, etc.
▪ She works for a big company. ▪ He organized a big advertising campaign. ▪ We had a big fund-raiser for the school. 4 always used before a noun a : tending to do something more often than most people
▪ He's a big eater. [=he often eats large amounts of food] ▪ She's a big shopper. [=she shops often]
b : feeling or showing a lot of excitement or enthusiasm
▪ I'm a big fan of their music. ▪ He gave me a big smile/hug. 5 : important or significant
▪ She became a big star in movies. ▪ He's big in local politics. ▪ The changes will have a big [=major] impact on the community. ▪ Our biggest concern is for the safety of the children. ▪ This job is my big chance. ▪ The movie was a big flop. ▪ They have big plans for the future. ▪ She was a big [=great] help during his illness. ▪ Buying this car was a big [=serious] mistake. ▪ I was nervous in the weeks leading up to the wedding day, but felt surprisingly calm on the day of the big event. ▪ Tomorrow is the big day. [=the day that something important happens] ▪ Her suggestion made a big difference [=led to important changes] in the final product. ▪ She wanted to go in a big way. [=very much, badly] — see also big deal, big picture 6 always used before a noun, informal — used to express strong dislike or disapproval ▪ You're nothing but a big sissy/bully! ▪ If you marry her you're an even bigger fool [=you're even more of a fool] than I thought you were! 7 informal : older or more grown up
▪ my big [=older] sister/brother ▪ He's a big boy now. [=he is less like a baby now] — see also big boys, big brother 8 : very popular
▪ That toy is always a big seller. ▪ The band was a big hit abroad. ▪ Her books are big with teenagers. ▪ She thinks longer skirts will be big this year. ▪ Designers will discuss the next big thing [=a future trend] in home decorating. 9 : generous or kind
▪ It was big of him to forgive them after the way they treated him. ▪ She was big about it and invited him along. ▪ He has a big heart. [=he is a kind person] — sometimes used in an ironic way to say that someone is not being very generous or kind ▪ You can spare us a whole five minutes of your time? Well, that's big of you! — see also big-hearted 10 : very strong, forceful, etc.
▪ There was a big [=powerful] storm last night.