Green’s Dictionary of Slang

1. (US) high on drugs or caffeine; thus in fig. use, nervous.

1970		R. Gilmore Drug Education Hbk.
1981		in National Instit. on Drug Abuse Gloss.
1994		J. Wambaugh Finnegan’s Week 173: Too much caffeine [...] I’m so amped I could jump-start Frankenstein’s monster.
1998		Source Nov. 138: Eric Bobo plays a vital part in the group’s amped up performances.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 583: Like: Bob Relyea — nervous and hi-amped.
2013		J. Stahl Bad Sex on Speed 34: And right in front of you, she starts cutting her thighs [...] Amped-up and serene.

2. (US) increased, intensified, augmented.

1970		Psychic Discoveries behind the Iron Curtain 230: Acupuncture has been amped-up , modernized , combined with EEGs , electrocardiograms , etc.
2020		(con. 1991-94) W. Boyle City of Margins 10: Donnie’s been into this from the start, but it’s amped up since Gabe’s death.

3. (US, also amp, amped up) stirred up, very emotional; ready, enthusiastic.

1977		L. Pearson Out of Work 26: Sheila was amped up like it was New Year's Eve.
1985		‘Jennifer Blowdryer’ Modern English 4: Some who is amped is freaky, weird, their volume is too high.
1989		Public Enemy ‘Fight the Power’ 🎵 I’m hyped, plus I’m amped.
1990		N. George ‘Superfly’ in Buppies, B-Boys, Baps and Bohos (1994) 118: Another Saturday at Dapper Dan’s [...] and the hip-hop boutique [...] is amped.
1992		D. Burke Street Talk 2 59: I’ve never seen you so amped up.
1994		G. Smitherman Black Talk 49: amp Stirred up; in a heightened emotional state.
2004		Eble Campus Sl. Apr. 1: amped – excited.
2009		J. Stahl Pain Killers 169: You over there all amped up like you dialed into some secret-ass information.
2010		Codella and Bennett Alphaville (2011) 231: All three of us were amped on adrenaline.
2012		‘Dutch’ ? (Pronounced Que) [ebook] Gutta wasn’t his usually amped self who rocked from head to foot.
2016		New Yorker 11 Aug. 🌐 His buddy was amped up, though, claiming his friend hadn’t done anything. I shot back that was horse hockey—yes, he had.
2021		Central Cee ‘The Bag’ 🎵 When I think ’bout that, it get man amped.