Green’s Dictionary of Slang

kick-ass adj.

also kick-arse, kick-butt, kick(s)-in-the-ass
[kick ass v.]
(orig. US)

1. powerful, aggressive, stimulating, thuggish or violent.

[US] in Merriam-Webster’s Collegiate Dict. (1998).
[US]E. Torres Q&A 164: ‘You just got out of school, Reilly. I been in the kicks-in-the-ass school all my life’.
[US]R. Marcinko Rogue Warrior (1993) 210: I need a kick-ass admin officer.
[US]M. Myers et al. Wayne’s World II [film script] wayne: I’m talking double-live, gonzo, kick-ass, take-no-prisoners happiness.
[US]R. Campbell Wizard of La-La Land (1999) 18: In spite of the kick-in-the-ass jumpstart Joseph Campbell’s PBS series had given them.
[UK]Indep. on Sun. 16 Jan. 24: Suddenly, he was six-feet-two of kick-butt Home Secretary.
[UK]M. Manning Get Your Cock Out 92: They started banging around on the drums and bass, searching for kick-ass riffs.
[Aus]L. Redhead Rubdown [ebook] His openness was engaging and made you want to respond in kind. Especially after a kick-arse double expresso.
[US]J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 248: I’ve got a kick-ass will and volition.
[Aus]P. Temple Truth 132: In the kickarse voice Villani heard the boy who never had a father, only a photograph.
Pando Qly Spring 52/2: The quietest and most modest kick-ass brilliant mind ever to come out of North Carolina.
[UK]A. Wheatle Crongton Knights 134: Some hot chick from a kick-ass fam.
[Aus]C. Hammer Silver [ebook] A kick-arse journo.
H. Joyce Trans 55: [E]ven the most kick-ass woman [...] stands by her man.

2. terrific, exciting.

[US](con. 1967) P. Conroy Lords of Discipline 378: Man, we had a great night. A fabulous kiss-ass night.
[US]Eble Campus Sl. Oct. 4: kick-ass – impressive, powerful, awesome: That was some kick-ass rock and roll.
[US]Eble Campus Sl. Apr.
[US]People (Sydney) 5 July 18/1: Devised by an ex-Grenadier Guard to sort the men from the soft cocks, the kick-arse event has been running for the past 12 years.
[UK](con. 1979–80) A. Wheatle Brixton Rock (2004) 136: A tournament in which the top kick-arse sounds in London would musically cross swords.
[UK]Guardian Guide 5–11 Feb. 28: The world was so boring before kick-ass crazy guys like myself [...] made all this mad culture that is now part of the culture.
[US]S. King Dreamcatcher 7: Jackson Browne [...] put on a kick-ass show.
[US]T. Dorsey Stingray Shuffle 149: I spent the money on a six-month kick-ass cocaine party.
[Aus]L. Redhead Peepshow [ebook] We’ll have to go out some time for a kick-arse curry.
[US]Codella and Bennett Alphaville (2011) 224: Yo, get your Hot One-Oh-Three here. Got that kick-ass shit, yo! Kick-ass D!
[SA]IOL News On Line (S.Afr.) 10 Mar. 🌐 I love the kick-ass slogans.
[UK]Times Times2 6 Jan. 🌐 CW will happily declare Ferguson’s reply to be one of the most kick-ass things of 2017.
[Aus]C. Hammer Opal Country 335: ‘Stuff the caring professions. I wanted a kick-arse profession’.

In derivatives

kick-assness (n.)

pugnacity.

J.K. Rowling on Twitter 20 Dec. 🌐 @jessphillips your kick-assness is a constant inspiration x.