'loosen up' definitions:

Definition of 'loosen up'

(from WordNet)
verb
Cause to become unblocked; "The medicine unstuffed my nose in minutes!" [syn: unstuff, loosen up] [ant: block, choke up, lug, stuff]
verb
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" [syn: relax, loosen up]
verb
Make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity [syn: limber up, warm up, loosen up]
verb
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" [syn: relax, loosen up, unbend, unwind, decompress, slow down] [ant: tense, tense up]
verb
Cause to feel relaxed; "A hot bath always relaxes me" [syn: relax, unstrain, unlax, loosen up, unwind, make relaxed] [ant: strain, tense, tense up]

Synonyms of 'loosen up'

From: Moby Thesaurus

Words containing 'loosen up'