tower exhibiting lights to warn mariners of rocks, shoals, etc., 1620s, from light (n.) + house (n.).
Entries linking to lighthouse
light n.
"brightness, radiant energy, that which makes things visible," Old English leht (Anglian), leoht (West Saxon), "light, daylight; spiritual illumination," from Proto-Germanic *leukhtam (source also of Old Saxon lioht, Old Frisian liacht, Middle Dutch lucht, Dutch licht, Old High German lioht, German Licht, Gothic liuhaþ "light"), from PIE root *leuk- "light, brightness."
The -gh- was an Anglo-French scribal attempt to render the Germanic hard -h- sound, which has since disappeared from this word. The figurative spiritual sense was in Old English; the sense of "mental illumination" is first recorded mid-15c. Meaning "something used for igniting" is from 1680s. Meaning "a consideration which puts something in a certain view" (as in in light of) is from 1680s. Short for traffic light from 1938. Quaker use is by 1650s; New Light/Old Light in church doctrine also is from 1650s. Meaning "person eminent or conspicuous" is from 1590s. A source of joy or delight has been the light of (someone's) eyes since Old English:
Ðu eart dohtor min, minra eagna leoht [Juliana].
Phrases such as according to (one's) lights "to the best of one's natural or acquired capacities" preserve an older sense attested from 1520s. To figuratively stand in (someone's) light is from late 14c. To see the light "come into the world" is from 1680s; later as "come to full realization" (1812). The rock concert light-show is from 1966. To be out like a light "suddenly or completely unconscious" is from 1934.
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]