Green’s Dictionary of Slang

1. (later use Aus.) to look at, to stare.

1718		C. Hitchin Regulator 20: The Cull gigs, alias the Man looks.
1768		(con. 1710–25) Tyburn Chronicle II in Groom (1999) xxviii: The Cull giggs The Man looks.
1786		Whole Art of Thieving [as cit. 1718].
1984		B. Ellem Doing Time app. C 228: I don’t want outsiders gigging at me, or the authorities showing me off to them.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Gig. 1. To look.
1904		Sun. Times (Perth) 13 Mar. 11/3: I’m Hartmann whose rummy old rig / All gutter-bred larrikins gig.

2. (Aus., also gig about) to look on when one ought to be working.

1944

T. Hartley gloss. in Simes DAUS (1993) 92/1: Gigging about — looking on when you should be working.