O.E. bur "room, hut, dwelling, chamber," from P.Gmc. *buraz (cf. O.N. bur "chamber," Swed. bur "cage," O.H.G. bur "dwelling, chamber," Ger. Bauer "birdcage"), from base *bu- "to dwell," from PIE base *bheue- "to be, exist, dwell" (see
be). Modern spelling developed after mid-14c.
Sense of "leafy arbor" (place closed in by trees) is first attested 1520s. Hence, too, Australia's bower-bird (1847).