Green’s Dictionary of Slang

kill adj.

[abbr. killer adj.; on bad = good model]

(US) fashionable, smart, sophisticated.

1982		S. Black Totally Awesome 122: I just saw this kill movie [HDAS].
1993		P. Munro U.C.L.A. Sl. II n.p.: They got some kill buds for tonight [HDAS].