late 14c., transitive "to bathe (a person or a body part) in a steam bath," from Old French estuver "have a hot bath, plunge into a bath; stew" (Modern French étuver), of uncertain origin. Common Romanic (cognates: Spanish estufar, Italian stufare), possibly from Vulgar Latin *extufare "evaporate," from ex- "out" + *tufus "vapor, steam," from Greek typhos "smoke." Compare Old English stuf-bæþ "hot-air bath;" see stove.
Intransitive use from 1590s. Meaning "to boil slowly, to cook meat by simmering it in liquid" is attested from early 15c. The meaning "to be left to the consequences of one's actions" is from 1650s, especially in figurative expression to stew in one's own juices. Related: Stewed; stewing. Slang stewed "drunk" first attested 1737.
"sebaceous secretion," 1819, from Latin, from Greek smēgma "a detergent, soap, unguent," from smēkhein "to wipe off, wipe clean, cleanse," from PIE root *smeh- "to smear" (source also of Czech smetana "cream," and see smear (v.)). So called from resemblance of the substance to soap; a medical coinage, the word seems not to have been used in its literal Greek sense in English before this. Related: Smegmatic.
also bath-room, 1780, from bath + room (n.). Originally a room with apparatus for bathing (the only definition in "Century Dictionary," 1902); it came to be used 20c. in U.S. as a euphemism for a lavatory and often is noted as a word that confuses British travelers. To go to the bathroom, euphemism for "relieve oneself; urinate, defecate," is from 1920 (in a book for children), but typically is used without regard for whether an actual bathroom is involved.
"act of washing, a cleansing," 1620s, from Latin lavationem (nominative lavatio) "a bathing, bath, bathing apparatus," noun of action from past-participle stem of lavare "to wash" (from PIE root *leue- "to wash"). Related: Lavations.
Old English leaþr "foam, soap, washing soda," from Proto-Germanic *lauthran (source also of Old Norse lauðr "washing soap, foam"), from PIE *loutro- (source also of Gaulish lautron, Old Irish loathar "bathing tub," Greek louein "to bathe," Latin lavere "to wash"), which is from root *leue- "to wash" + instrumentative suffix *-tro-.
The modern noun might be a 16c. redevelopment from the verb. Meaning "violent perspiration" (especially of horses) is from 1650s; hence the transferred sense "state of agitation" (such as induces sweating), attested from 1839.
plant native to Mexico and the southern U.S., by 1831, in a California context, from Mexican Spanish amole, name for various plant-roots used as detergents, from Nahuatl (Aztecan) amolli "soap-root."
"Western film" (featuring horse-riding cowboys and Indians), 1946, American English, from oat, as the typical food of horses. Oats opera (on the model of soap opera) is by 1937 in U.S. slang.
type of whirlpool bath, 1961, U.S. proprietary name, from Jacuzzi Brothers, then headquartered in California, who earlier made jet pumps for motorboats. The family immigrated from Friuli in northern Italy.
"Finnish steam bath," also the house or room where it is taken, 1881, from Finnish sauna. Originally in a Finnish context; by 1959 in reference to installation in homes and gyms outside Finland.