bracket

Concise Oxford English Dictionary © 2008 Oxford University Press:
bracket/ˈbrakɪt/

▶noun

• 1 each of a pair of marks ( ) [ ] { } 〈 〉 used to enclose words or figures and separate them from the surrounding context.

• 2 a category of similar people or things.

• 3 a right-angled support projecting from a wall, holding a shelf, lamp, etc.

• 4 Military the distance between two artillery shots fired either side of the target to establish range.

▶verb (brackets, bracketing, bracketed)

• 1 enclose (words or figures) in brackets.

  ■ Mathematics enclose (a complex expression) in brackets to denote that the whole of the expression has a particular relation to another expression.

• 2 place in the same category.

• 3 attach by means of a bracket.

• 4 Military establish the range of (a target) by firing preliminary shots short of and beyond it.

– origin C16: from Fr. braguette or Sp. bragueta ‘codpiece, bracket, corbel’, from Provençal braga, from L. braca, (pl.) bracae ‘breeches’.