houseboat (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]

"small open vessel (smaller than a ship) used to cross waters, propelled by oars, a sail, or (later) an engine," Old English bat, from Proto-Germanic *bait- (source also of Old Norse batr, Dutch boot, German Boot), possibly from PIE root *bheid- "to split," if the notion is of making a boat by hollowing out a tree trunk or from split planking. Or it may be an extension of the name for some part of a ship.

French bateau "boat" is from Old English or Norse. Spanish batel, Italian battello, Medieval Latin batellus likewise probably are from Germanic. Of serving vessels resembling a boat, by 1680s. The image of being in the same boat "subject to similar challenges and difficulties" is by 1580s; to rock the boat "disturb stability" is from 1914.