warms up; warmed up; warming up
1 : to become warmer
After being outside too long, I'm slowly warming up.
The days are starting to warm up.
2 warm up or warm (something) up or warm up (something) : to do exercises in order to prepare for some activity (such as a sport)
You should always warm up for a few minutes before you begin to run.
The singer warmed up her voice before the concert.
3 : to start to do something that you will do in a more intense way later : to become more intense or enthusiastic
He's just warming up; he's saving his best material for the end.
The party finally warmed up [=heated up] after a couple of hours.
4 warm (someone) up or warm up (someone) : to entertain (people) before a show begins
The comedian warmed up the audience before the concert.
5 a of a machine : to become ready for use after being started or turned on
I always let the car warm up for a couple of minutes in the winter before I start driving.
5 b warm (a machine) up or warm up (a machine) : to cause or allow (a machine) to become ready for use after being started or turned on
The engine needs to be warmed up for a couple of minutes.