1. to warm up
It's important to warm up before the match.
2. heat up
You’ll have to heat up the soup because it’s in the fridge.
I quite often have ready-made soups that you onlyhave to heat up.
I usually heat up a frozen meal.
heat up soup
Come to the kitchen, I'll heat up the omelet. / 2. We need to heat up the soup. / 3. She's heating up the soup.
3. heat something up