Wiktionary
a. 1 (context of a tyre etc English) inflated 2 (context of water English) raised by pumping 3 (context of a person English) tense with excitement or enthusiasm
WordNet
adj. tense with excitement and enthusiasm as from a rush of adrenaline; "we were really pumped up for the race"; "he was so pumped he couldn't sleep" [syn: pumped-up(a), pumped up(p), pumped(p), wired]
Usage examples of "pumped-up".
Anyway, Sean Penn is this pumped-up lowlife going nowhere in a nowhere town until one day he discovers his long-lost father, Christopher Walken, acting even weirder than usual, is this cool criminal type he can really look up to because what else is he gonna do with an eighth grade education and a constipated strut and these ridiculous biceps swelling out of his T-shirt like Sunday hams?