Green’s Dictionary of Slang

(US black teen) in a relaxed, stress-free state of mind.

1988		Ice-T ‘Grand Larceny’ 🎵 And once I’m in effect it’s overkill.
2002		‘Touré’ Portable Promised Land (ms.) 158: We Words (My Favorite Things) [...] In effect mode.

1. efficiently.

1991		Tribe Called Quest ‘Check the Rhime’ 🎵 I come correct, in full effect.
2008		R. Price Lush Life 230: I cannot work this in full effect if I have to be worried about you too .

2. (orig. US black) present, going on, happening.

1994		P. Baker Blood Posse 156: From now on the Robin Hood style is in full effect.
1997		Simon & Burns Corner (1998) 527: The corner has its own rules, and number two — never say never — is always in full effect.
1998		Hip-Hop Connection Dec. 16: Busta Rhymes’ Flipmode Squad are finally in full effect.
1999		J. Ridley Everybody Smokes in Hell 3: The cruising Mexicans and the gang kids were in full effect.
2002		‘Touré’ Portable Promised Land (ms.) 158: We Words (My Favorite Things) [...] In effect mode. In full effect.
2006		Burns & Price ‘Corner Boys’ Wire ser. 4 ep. 8 [TV script] Damn. You all comin’ along in full effect. I hear that.

(N.Z. prison) phr. that implies one’s indifference to a threatening or problematic statement or situation.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 125/1: no effect int. an expression displaying indifference to a given threat or negative situation, conveying emotional security and a lack of concern or upset.