1825, "a residence in a town," from town + house (n.) from a time when well-off families had country houses as well. As a type of suburban attached housing, c. 1968, American English.
Entries linking to townhouse
town n.
Old English tun "enclosure, garden, field, yard; farm, manor; homestead, dwelling house, mansion;" later "group of houses, village, farm," from Proto-Germanic *tunaz, *tunan "fortified place" (source also of Old Saxon, Old Norse, Old Frisian tun "fence, hedge," Middle Dutch tuun "fence," Dutch tuin "garden," Old High German zun, German Zaun "fence, hedge"), an early borrowing from Celtic *dunon "hill, hill-fort" (source also of Old Irish dun, Welsh din "fortress, fortified place, camp," dinas "city," Gaulish-Latin -dunum in place names), from PIE *dhu-no- "enclosed, fortified place, hill-fort," from root *dheue- "to close, finish, come full circle" (see down (n.2)).
Meaning "inhabited place larger than a village" (mid-12c.) arose after the Norman conquest from the use of this word to correspond to French ville. The modern word is partially a generic term, applicable to cities of great size as well as places intermediate between a city and a village; such use is unusual, the only parallel is perhaps Latin oppidium, which occasionally was applied even to Rome or Athens (each of which was more properly an urbs).
First record of town hall is from late 15c. Town ball, version of baseball, is recorded from 1852. Town car (1907) originally was a motor car with an enclosed passenger compartment and open driver's seat. On the town "living the high life" is from 1712. Go to town "do (something) energetically" is first recorded 1933. Man about town "one constantly seen at public and private functions" is attested from 1734.
house n.
Old English hus "dwelling, shelter, building designed to be used as a residence," from Proto-Germanic *hūsan (source also of Old Norse, Old Frisian hus, Dutch huis, German Haus), of unknown origin, perhaps connected to the root of hide (v.) [OED]. In Gothic only in gudhus "temple," literally "god-house;" the usual word for "house" in Gothic being according to OED razn.
Meaning "family, including ancestors and descendants, especially if noble" is from c. 1000. Zodiac sense is first attested late 14c. The legislative sense (1540s) is transferred from the building in which the body meets. Meaning "audience in a theater" is from 1660s (transferred from the theater itself, playhouse). Meaning "place of business" is 1580s. The specialized college and university sense (1530s) also applies to both buildings and students collectively, a double sense found earlier in reference to religious orders (late 14c.). As a dance club DJ music style, probably from the Warehouse, a Chicago nightclub where the style is said to have originated.
To play house is from 1871; as suggestive of "have sex, shack up," 1968. House arrest first attested 1936. House-painter is from 1680s. House-raising (n.) is from 1704. On the house "free" is from 1889. House and home have been alliteratively paired since c. 1200.
And the Prophet Isaiah the sonne of Amos came to him, and saide vnto him, Thus saith the Lord, Set thine house in order: for thou shalt die, and not liue. [II Kings xx.1, version of 1611]