Green’s Dictionary of Slang

1. (US) intense, strong.

1970		T. Southern Blue Movie (1974) 174: Why don’t we do some full-on S.M.?
1991		M.B. ‘Chopper’ Read Chopper From The Inside 118: There were full-on attempts by Dennis and his crew on my life.
2001		N. Barlay Hooky Gear 124: Trudy got him folded an wrapped for a full-on LTR.
2004		L. Redhead Peepshow [ebook] Must have been full on, middle of a murder investigation.
2010		K. Richards Life 341: One of those full-of-brass, full-on guys.

2. (US) total, absolute, complete, utter.

1986		H.B. Gilmour Pretty in Pink 99: I’m a full-on drive-by guy.
1986		R.G. Barrett Godson 65: [H]is full on, car dealer’s spiel.
1992		R.G. Barrett Davo’s Little Something 41: He was about [...] the best-looking guy in the place, yet in a natural, manly but not too full-on macho sort of way.
2005		A. Lovejoy Acid Alex 101: Somebody concluded that if I didn’t know what the boere were called then I had to be a full-on skaap.
2006		B. Matthews Intractable [ebook] I had just survived a hectic full-on shoot ’em up car chase.
2009		T. Black Gutted 61: At the traffic lights [...] I spotted an act of full-on nuttery in progress.
2011		Sowetan (Johannesburg) 24 June 🌐 Major focus areas will be vocal production [...] and introduction of a full-on hip-hop dissection by leaders in the field.
2012		L. Redhead ‘Grassed’ in Crime Factory: Hard Labour [ebook] Sharni had busted her and it turned into a full on scrag fight.