Meaning

noun tree (as opposed to shrub)

noun any of various rotating shafts that serve as axes for larger rotating parts

noun a framework that supports climbing plants

originFrom Middle English arbour, erbour, from Old French erbier (“field, meadow, kitchen garden”), from erbe (“grass, herb”), from Latin herba (“grass, herb”) (English herb). (Compare Late Latin herbārium, although erbier is possibly an independent formation.) The spelling was influenced by Latin arbor (“tree”).

Etymology from Wiktionary, CC BY-SA 3.0