Green’s Dictionary of Slang

(UK tramp/carnival) to talk, to speak; also as n., language, ‘lingo’.

1846		Swell’s Night Guide 59: Hang me high up! if it arn’t a Wild-street shickster — Owen’s mot! I’ll pallary to her. [Ibid.] 61: cracksman: [...] why, you nunk, couldn’t you tumble to the pallary, nanty tumble to the queerums, a foggy nobbed’un?
1850		Man of Pleasure’s Illus. Pocket-book n.p.: ‘Hang me high up! if it arn’t a Wild-street shickster — Owen’s mot! I’ll pallary to her’.
1893		P.H. Emerson Signor Lippo 59: Though they offered me lots of money to blow the gaff, I felt afraid to palarie a dickey for fear of being trapped by either the owner or trainer.
c.1965		Took & Feldman Round the Horne [BBC radio series] Hello! We’re from the Daily Palari, yes! Can we have five minutes of your time?