Wiktionary
vb. 1 (context intransitive English) to become loose; to loosen 2 (context colloquial English) to relax, act less seriously.
WordNet
v. cause to become unblocked; "The medicine unstuffed my nose in minutes!" [syn: unstuff] [ant: stuff]
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]
make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity [syn: limber up, warm up]
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, unbend, unwind, decompress, slow down] [ant: tense]
cause to feel relaxed; "A hot bath always relaxes me" [syn: relax, unstrain, unlax, unwind, make relaxed] [ant: tense, tense]
Usage examples of "loosen up".
But if the plebe could make Kirk loosen up some more, if he could unearth a person from that stack of textbook tapes, that would be satisfaction enough.
Then after fifteen long years they offered him a pardon, if he would loosen up with the loot.
As Michael began to thrust I felt my sex loosen up, accommodating his lovely cock.
The first to arrive was Helen D'Agustino, one of the President's personal bodyguards, who'd been walking the corridors to loosen up after sitting most of the day.