Green’s Dictionary of Slang

a blow on the nose.

1825		Pierce Egan’s Life in London 1 May 109/1: It was a nobber — a facer repeated—a rum one on the ivories—a nozzler, wound up by a tremendous ogler.
1828		Sporting Mag. 22 198: In the ninth round Bob received a nozzler drawing claret.
1829		Egan Boxiana 2nd Ser. II 188: Frank put in a tremendous nozzler, which almost made the Jew’s head dance a hornpipe.
1855		(con. 1824) Fights for the Championship 78: He [...] received a nozzler as he came in.