curl up phrasal verb (see also curl)

1. to move so that you are lying or sitting with your arms and legs bent close to your body:
I just wanted to curl up and go to sleep.
Sarah was curled up on the sofa.

2. if something flat curls up, its edges start to become curved and point upwards:
The letter was now yellow and beginning to curl up.

[TahlilGaran] Dictionary of Contemporary English ▲

curl up
v.
1a. To become curly or wavy.
Bacon curls up when it is cooked.
1b. To roll oneself into a ball.
Tim curled up in bed and was asleep in five minutes.
2. See: FOLD UP.

[TahlilGaran] English Idioms Dictionary ▲