ARBOR (2)

Ar″bor, n. [Written also arbour.] [] 1. 1. (Bot.) A tree, as distinguished from a shrub.
2. 2. [[Cf. F. arbre.]] (Mech.) (a) An axle or spindle of a wheel or opinion. (b) A mandrel in lathe turning. Knight.
Arbor Day, a day appointed for planting trees and shrubs.