1911 Encyclopædia Britannica/Arbour

ARBOUR, or Arbor (originally “herber” or “erber,” O. Fr. herbier, from Lat. herbarium, a collection of herbs, herba, grass; the word came to be spelt “arber” through its pronunciation, as in the case of Derby, and by the 16th century was written “arbour,” helped by a confusion of derivation from Lat. arbor, a tree, and by change of meaning), a grass-plot or lawn, a herb-garden, or orchard, and a shady bower of interlaced trees, or climbing plants trained on lattice-work. The application of the word has shifted from the grass-covered ground, the proper meaning, to the covering of trees overhead. “Arbor” (from the Latin for “tree”) is a term applied to the spindle of a wheel, particularly in clock-making.