bound·ary 
/ˈbaʊndri/ noun
plural bound·aries /ˈbaʊndri/ noun 1 [count] : something (such as a river, a fence, or an imaginary line) that shows where an area ends and another area begins
▪ Those two trees mark the boundary of our property. ▪ The river forms the country's western boundary. 2 [count] : a point or limit that indicates where two things become different
▪ at/on the boundary between fact and fiction 3 boundaries [plural] : unofficial rules about what should not be done : limits that define acceptable behavior
▪ You need to set boundaries with your children. ▪ Did he violate the boundaries of the doctor-patient relationship? ▪ They're pushing the boundaries of [=doing things that are unusual in] traditional French cooking.
▪ Those two trees mark the boundary of our property. ▪ The river forms the country's western boundary.
▪ at/on the boundary between fact and fiction
▪ You need to set boundaries with your children. ▪ Did he violate the boundaries of the doctor-patient relationship? ▪ They're pushing the boundaries of [=doing things that are unusual in] traditional French cooking.
know no boundaries 1 : to be capable of affecting people everywhere
▪ This is a disease that knows no boundaries. 2 : to have no limits
▪ My admiration for him knows no boundaries. [=knows no bounds]
▪ This is a disease that knows no boundaries.
▪ My admiration for him knows no boundaries. [=knows no bounds]
