noun A submarine (informal shortening).
- The sub surfaced a few miles offshore.
- The sailors spent six months living inside a sub deep under the ocean.
- A toy sub floated in the bath beside the rubber duck.
noun A substitute, especially a teacher or sports player standing in for another.
- We had a sub for math class today.
- The striker was injured, so the team brought on a sub.
- Our usual teacher was ill, so a sub took the lesson instead.
verb To act as a substitute for someone.
- She subbed for the regular teacher while he was ill.
- I'll sub for you at the front desk while you take your break.
- He subbed for the singer when she lost her voice.
verb To replace one player with another during a game.
- The coach subbed him out in the second half.
- The manager decided to sub the tired midfielder after seventy minutes.
- They subbed off their goalkeeper because of a sore ankle.
