Green’s Dictionary of Slang

cokir n.

a liar.

1665

16701680169017001710

1714

1665		Head Eng. Rogue I 48: Cokir, A Lyar.
1714		A. Smith Lives of Most Noted Highway-men, etc. I 209: He taught his Pupil a deal of canting Words, telling him [...] Cokir, a Liar.