spleenful \SPLEEN-fuhl, adjective:

1. Ill-humored; irritable or peevish; spiteful; splenetic.
2. Full of or displaying spleen.

For a blink, Ratcliffe himself, who hated almost beyond telling this spleenful fellowman now well handcuffed and clamped at the ankles with cold stout bilboes, did believe in his intentions, and would have resigned all proceedings if he could; but once the doctor prescribes a purge, how can he countermand himself?
— William T. Vollmann, Argall

Their attention was focused on Guy Fowler, a surly, spleenful man, but one of few old-salts of white blood.
— Virginia Van Druten, Bound to Sea

The spleen was regarded as the seat of morose feelings and bad tempers in Medieval physiology. The adjective spleenful arose from this association in the late 1500s.