Green’s Dictionary of Slang

1. to dress flashily, to dress up.

1928		L.A. Sigsworth Verse 2: The ‘babbling brook’ will let the guns lare up in the shearers’ mess [AND].
1941		Baker Popular Dict. Aus. Sl. 42: Lair up, to dress, esp. to don one’s best clothes for a festive occasion.
1987		Times on Sun. 14 June 14: She describes herself as a ‘casual person, not one to go out and lair up.’ [GAW4].
2000–02		Macquarie Dict. 🌐 4. lair up, a. to dress up in flashy clothes. b. to renovate or dress up something in bad taste.

2. (also lair it up) to act in a showy manner.

1928		Truth (Brisbane) 26 Aug. 4/8: Almost immediately, Carltons worked play into the Suburbs’ territory, where a bit of ‘lairing up’ by a Suburbanite gave Bill Kavanagh an opportunity to dive on the ball.
1937		Recorder (Port Pirie, SA) 19 Aug. 1/5: ‘I have heard women clients complain that their husband “lair up,”’ said Mr. Warren. [...] Plainclothes-Constable Hodge: ‘Lair up’ is an Australian term for ‘whoopee’.
1940		H. Drake-Brockman Hot Gold I i: It’s that Rienzi. He’s a trimmer. Always laring round.
1959		D. Niland Big Smoke 32: Only good for lairing up and beggarizing about with women.
1968		S. Gore Holy Smoke 51: It all begun in the first place with Him gettin’ pretty jack of the way all these booze artists and eeler-spielers and loose women, as they’re called, was lairin’ it up.
1996		(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 250: The egg-throwers were both so caught up lairing to their mates that they didn’t see us coming.
2000–02		Macquarie Dict. 🌐 3. lair it up, to behave in a brash and vulgar manner.