Green’s Dictionary of Slang

1. to ignore, to treat contemptuously, to dismiss.

1821		Egan Life in London (1869) 358: The engagements [...] are now made on such precarious terms, that he is liable to be brushed off at the end of the first season.
1914		E. Dyson Spats’ Fact’ry (1922) 39: Brush ’em off girls; they ain’t no good t’ yeh. They’re deliberit take-downs, who’ve planned a way out afore enterin’ into the flirtation.
1942		N. Algren Never Come Morning (1988) 155: Charlie had seduced them all, had spent their money like water and brushed them off without a qualm.
1953		R. Mais Hills were Joyful Together (1966) 46: Cho man, Ah brush you off.
1969		M. Puzo Godfather 63: Hey, Casanova, those broads really brushed you off.
1982		Maledicta VI:1+2 (Summer/Winter) 134: Trying to investigate lesbian lingo, I have encountered some politically motivated hostility; even my female helpers if detected as not sympatica have been cold-cunted and brushed off.
1986		R.G. Barrett Real Thing 85: So Colin brushed Easts not long after Les.
1992		M. Coleman Fatty 233: ‘I virtually agreed to terms but in the end they signed Rowdy and brushed me’.
1999		R.G. Barrett Wind & Monkey (2013) [ebook] Les brushed the talkback waffle and slipped in a cassette.
2000		(con. 1940s–60s) Décharné Straight from the Fridge Dad 21: Brush To ignore someone.
2000		F. Kellerman Stalker (2001) 99: Stop brushing me off and just listen.

2. (US Und.) to murder.

1949

Monteleone Criminal Sl. (rev. edn).

3. see brush v.¹