Green’s Dictionary of Slang

a mendicant tramp.

1713		R. Wodrow Analecta II (1842) 165: I think he went about his trade to a fair; and there is a gang of tinklers he had been intimate with before, and almost a ringleader to them.
1724		A. Ramsay Tea-table Misc. (1733) I 96: For lady fair, tho’ I appear To every ane a tinkler [...] I am a gentle jinker.
1786		Burns The Jolly Beggars in Works (1842) 11/1: Poor Merry Andrew in the neuk, Sat guzzling wi’ a tinkler hizzie.
a.1796		Burns ‘Bonie Mary’ in Merry Muses of Caledonia (1965) 51: An’ was nae Wattie a Clinker? / He maw’d frae the queen to the tinkler .
1830		J. Galt Lawrie Todd I Pt I 9: A gang of tinklers, with smiddy bellows [...] came to the town.
1847		C. Brontë Jane Eyre II 84: Yes, ma’am, but she looks such a tinkler.