-lagnia

Morbid sexual arousal.

Greek lagneia, lust.

These are principally technical terms in psychiatry. Examples include urolagnia (Greek ouron, urine), a tendency to derive sexual pleasure from the sight or thought of urination; algolagnia (Greek algos, pain), desire for sexual gratification through inflicting pain on oneself or others; coprolagnia (Greek kopros, dung), sexual arousal by the thought or sight of feces.