Green’s Dictionary of Slang

(US/W.I.) to cast one’s suspicions at/upon.

1907		‘Calcutta Monkey and Annancy’ in W. Jekyll Jam. Song and Story 117: Monkey went to Annancy yard an’ suspish upon Annancy.
1944		Californian (Salinas, CA) 26 Sept. 11/3: I suspish if my wife Topaz behole dis much beans on one stawk she catch a swoon!