Green’s Dictionary of Slang

(US) excellent, worthy of admiration.

1956		R. Ellison ‘A Coupla Scalped Indians’ in King Black Short Story Anthol. (1972) 266: I bet with them she could work up some outrageous spells!
1977		N.Y. Times Mag. 19 June 66: ‘Outrageous’, spoken with heavy emphasis on the ‘rage’ and overweening approval in the voice, is today’s slang for defiant or flamboyant behavior, going against the rules.
1990		W.D. Myers Mouse Rap 11: When you first scope her you think that she’s kind of fine, but not really outrageous.
1996		Eble Sl. and Sociability 56: The following functionally synonymous slang terms from two school years, 1990–91 and 1991–92, all mean ‘excellent, worthy of approval’: [...] outrageous, righteous, ripping.
2019		P. Baker Fabulosa 296/1: outrageousextrovert, loud, camp .
2020		C. von Ziegesar Cobble Hill 54: The surf is outrageous and the food is too. I love it here.