clift, n. — Green’s Dictionary of Slang

clift n.

also cleft

[? SE cleave, i.e. their brain has been cut in several pieces]

(orig. Irish) a fool; thus the levels of stupidity, quarter clift, three-quarter clift, the two ends of a clift, an utter fool.

1910		P.W. Joyce Eng. As We Speak It In Ireland.
1997		Share Slanguage.