piss: [13] Piss probably originated in imitation of the sound of urinating. It has been traced back to a hypothetical Vulgar Latin *pisāre, which passed into English via Old French pisser. It has become widely distributed throughout the other European languages (Italian pisciare, for instance, German and Dutch pissen, and Welsh piso). Pee [18] started life as a euphemism for piss. => pee
late 13c., from Old French pissier "urinate" (12c.), from Vulgar Latin *pissiare, of imitative origin. To piss away (money, etc.) is from 1948. Related: Pissed; pissing. Pissing while (1550s) once meant "a short time."
He shall not piss my money against the wall; he shall not have my money to spend in liquor. [Grose, "Classical Dictionary of the Vulgar Tongue," 3rd edition, 1796]
late 14c., from piss (v.). As a pure intensifier (piss-poor, piss-ugly, etc.) it dates from World War II. Piss and vinegar first attested 1942. Piss-prophet "one who diagnosed diseases by inspection of urine" is attested from 1620s. Piss proud "erect upon awakening" is attested from 1796.
