Q: Where does “pissed off” (as in “angry”) come from? I know this sounds like a joke, but it’s a serious question!
A: Our serious answer begins around the year 1300, when English adopted the verb “piss” from the Anglo-Norman pisser.
Although the word is “now chiefly coarse slang,” according to the Oxford English Dictionary, it meant simply “urinate” back then.
The dictionary notes that “piss” is “probably ultimately of imitative origin”—that is, it represents the hissy sound of peeing.
The OED’s first citation for the verb is from the South English Legendary, a collection of lives, or biographies, of saints and other church figures.
In the life of St. James the Great (i.e., the Apostle James), the devil persuades a young pilgrim to castrate himself and commit suicide. James brings the pilgrim back to life, but doesn’t undo the castration:
“His menbres þat he carf of, euer-eft he dude misse Bote a luytel wise ȝware-þoruȝ he miȝhte, ȝwane he wolde, pisse” (“He did forever miss the member that he cut off, leaving a little stub through which he might urinate”).
Over the years, the verb “piss” came to be used figuratively in various expressions, including “piss money against the wall” (squander, 1540), “piss on someone” (show contempt, before 1625), “piss against the wind” (waste one’s time, 1642), and “piss and moan” (complain, 1948).
The noun “piss” first appeared sometime before 1387 in John Trevisa’s English translation of Polychronicon, a Latin chronicle by the Benedictine monk Ranulf Higden:
“Þey þrewe on his heed wommen pisser out of a chambre” (“They threw on his head women’s urine out of a chamber pot”).
Like the verb, the noun later took on some additional meanings, including its use as an intensifier in such phrases as “piss poor” and “piss elegant,” which we discussed in a post six years ago.
And like the verb, the noun “piss” meant simply “urine” in the 14th century, and wasn’t considered “coarse slang,” according to the OED.
When the adjective “pissed” showed up in the early 17th century, Oxford says, it referred to something “that has been urinated on or in; wet or stained with urine.”
The dictionary’s earliest example is from The Alchemist, a 1612 comedy by Ben Jonson: “Wrap’d up in greasie leather, or piss’d clouts.” (“Clouts” were pieces of cloth.)
It’s unclear from the OED citations exactly when “piss” came to be seen as coarse or vulgar.
In the early 19th century the adjective came to mean “drunk.” Here’s an example from John Bell’s Rhymes of Northern Bards (1812): “Sit still you pist fool!”
And in the mid-20th century, the adjective “pissed” took on the sense you’re asking about: angry, irritated, fed up.
In British use, the OED says, it’s frequently seen in the phrase “pissed off.” We’d add that the phrase is probably just as common in the US. In fact, the dictionary’s earliest citation is from an American memoir.
In Artist at War (1943), the American artist George Biddle writes of his experiences in Italy and Africa during World War II: “When I’m pissed off, I always get that starry look.”
The phrasal verb “piss off” showed up in writing just after the war, in a 1946 issue of the journal American Speech: “He pissed (or peed) me off. An expression used of a person who in any way disappointed the speaker.”
Finally, the phrasal verb “piss off” is also used (primarily in the UK) to mean “Go away!” or “Scram!”
The first OED citation is from The Mint, a memoir by T. E. Lawrence published after his death in 1935: “You piss off, Pissquick.” (Lawrence, an army colonel in World War I, describes enlisting anonymously after the war as an aircraftman in the Royal Air Force.)
from Grammarphobia http://www.grammarphobia.com/blog/2016/08/pissed-off.html