Dictionary definition · big
adjective
- above average in size or number or quantity or magnitude or extent"a large city"
- significant"graduation was a big day in his life"
- serious or severe"a bad headache"
- loud and firm"a big voice"
- conspicuous in position or importance"a big figure in the movement"
- prodigious"big spender"
- exhibiting self-importance"big talk"
- feeling self-importance"too big for his britches"
adverb
- extremely well"his performance went over big"
- in a boastful manner"he talked big all evening"
- on a grand scale"think big"
- in a major way"the play failed big at the box office"
Source: Open English WordNet (CC BY 4.0).