Urolagnia is a paraphilia

Paraphilia

Paraphilia is a biomedical term used to describe sexual arousal to objects, situations, or individuals that are not part of normative stimulation and that may cause distress or serious problems for the paraphiliac or persons associated with him or her...

 in which sexual excitement is associated with the sight or thought of urine or urination

Urination

Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...

. The term has origins in the Greek Language

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 (from ouron, urine, and lagneia, lust).

Those who enjoy urolagnia may enjoy urinating on another person or persons, or being urinated upon. Some participants may drink the urine; this practice is known as urophagia

Urophagia

Urophagia is the consumption of urine. There are various reasons that humans may consume urine. Urine was used in several ancient cultures for various health, healing, and cosmetic purposes, practices which are still used by some people of these cultures today...

, though uraphagia refers to the consumption of urine regardless of whether the context is sexual.