Green’s Dictionary of Slang

(Aus.) completely, whole-heartedly.

1984		D. Jenkins Life Its Ownself (1985) 57: She would be all-out, full-on, no-holds-barred tolerant.
1991		M.B. ‘Chopper’ Read Chopper From The Inside 18: Had Terry carried on and entered the criminal world full on, he would have been a force to be reckoned with.
2007		D. McDonald Luck in the Greater West (2008) 104: The dickheads who [...] were full-on into the religion.
2014		me-stepmums-too-fuckin-hot-mate at www.fakku.net 🌐 You’re pretty cute [...] so I kinda went an’ full-on pashed you.