Learner's definition of WARMUP
an exercise or set of exercises done to prepare for a sport or other activity
— often plural
something done before something else to prepare an audience, a group, etc., for the next thing
— usually singular
This presentation is just a warmup for the big session tomorrow.
Dinner is just a warmup. You should see what we're having for dessert!
He's just the warmup act.
comfortable clothing worn by athletes while they are preparing for competition
— usually plural
— called also
see also warm up at 2warm