loosen up vs unblock

loosen up and unblock both are verbs.

Word	Noun	Adjective	Verb	Adverb
loosen up	No	No	Yes	No
unblock	No	No	Yes	No

As verbs, unblock is a hyponym of loosen up; that is, unblock is a word with a more specific, narrower meaning than loosen up:

loosen up (verb)	unblock (verb)
become less tense, rest, or take one's ease	make (assets) available
cause to feel relaxed	play the cards of (a suit) so that the last trick on which a hand can follow suit will be taken by a higher card in the hand of a partner who has the remaining cards of a combined holding
make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity	clear or remove an obstruction from
cause to become unblocked
become less tense, less formal, or less restrained, and assume a friendlier manner