Green’s Dictionary of Slang

cleaver n.¹

a butcher.

1900		Sporting Times 3 Mar. 7/1: The event was celebrated by the appearance of a band of butchers [...]. A halt in front of the Pink ’Un office to cheer the staff was resented by the police, and the unsympathetic City bobbies moved the cleavers on.
1937–84		Partridge DSUE (1984) 224/1: C.18–19.