loosen up

verb

1. 1

   cause to feel relaxed

   A hot bath always relaxes me

2. 2

   become less tense, rest, or take one's ease

   He relaxed in the hot tub

   Let's all relax after a hard day's work

3. 3

   make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity

4. 4

   cause to become unblocked

   The medicine unstuffed my nose in minutes!

5. 5

   become less tense, less formal, or less restrained, and assume a friendlier manner

   our new colleague relaxed when he saw that we were a friendly group