loo
n. countablen. a common word for a toilet. It is mostly used in British English and is a bit more casual than 'bathroom' or 'restroom'.
n. a toilet or a room containing a toilet. Primarily British in usage; informal in register but generally considered polite enough for most social situations.
I'll be back in a minute; I'm just going to the loo.
The pub was crowded, and there was a long queue for the ladies' loo near the back entrance.
While 'toilet' can sometimes sound overly direct in British social circles, 'loo' serves as a widely accepted euphemism that avoids the clinical tone of 'lavatory' or the Americanism 'restroom'.
Uncertain, although usually derived in some way from Waterloo, the site of Wellington's 1815 victory over Napoleon, likely via a pun based on water closet. Other suggested derivations include corruptions of French l'eau (“water”), lieu (“place”), lieux d'aisances (“'places of convenience': a lavatory”), lieu à l'anglaise (“'English place': a British-style lavatory”), bordalou (“a diminutive chamber pot”) or gardez l'eau (“'mind the water'”), via Scots gardyloo, formerly used in Edinburgh while emptying chamber pots out of windows; the supposed use of "Room 100" as the lavatory in Continental hotels; a popularisation of lew, a regional corruption of lee (“downwind”), in reference to shepherds' privies or the former use of beakheads on that side of the ship for urination and defecation; or a clipped form of the name of the unpopular 19th-century Countess of Lichfield Lady Harriett Georgiana Louisa Hamilton Anson, who was the subject of an 1867 prank whereby her bedroom's name-card was placed on the door to the lavatory, prompting the other guests to begin speaking of "going to Lady Louisa".
Clipped form of halloo.
Clipped form of lanterloo.
From French loup (“wolf; mask, eyemask”). Doublet of lobo, lupus, and wolf.
From Hindi लू (lū), ultmately from Sanskrit उल्का (ulkā, “flame”).
Clipped form of lieutenant.
Commonly used with the definite article ('the loo') even when the specific location is unknown to the listener.