v (idiomatic|intransitive) To become encouraged, reinvigorated, or cheerful; to summon one's courage or spirits.
v (idiomatic|intransitive|dated|early 1900's) To dress oneself up smartly; compare (obsolete) (term|buck) ("a fop, dandy")
v (idiomatic|transitive|colloquial) To pass on to higher authority for resolution. See also (term|pass the buck).