Green’s Dictionary of Slang

a member of the Provisional IRA.

1971		Manchester Guardian Weekly 13 Feb. 24: Mothers, egged on by the Provos, swore their lasses had been raped.
1982		G.V. Higgins Patriot Game (1985) 23: I thought you were after the IRA and I was going to be able to enjoy this unexpected little get-together, listening to stories about the Provos.
1993		I. Welsh Trainspotting 221: The only fuckers thit ever made a difference tae Billy wir the provos.
2000		T. Udo Vatican Bloodbath 22: Charley Uncle Norfolk Tango Company had been tracking Ryan O’Brian’s crack brigade of Provos for three days.