loosen up

verb

1. cause to become unblocked"The medicine unstuffed my nose in minutes!"
2. 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"
3. make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity
4. become less tense, rest, or take one's ease"He relaxed in the hot tub"
5. cause to feel relaxed"A hot bath always relaxes me"