Dictionary.net

The horn of an animal of the deer family, typically present only in the male. It differs from the HORNS of other animals in being a solid, generally branched bony outgrowth that is shed and renewed annually. The word antler comes from the Latin anteocularis, ante (before) + oculus (eye). (From Webster, 3d ed)

[Cf.] The male Cervidae, or true deer (and, in the case of the reindeer, the females also) have solid bony horns or antlers, shed yearly. Beginning with a single "dag," they add a fresh "tine, or " tyne," on each renewal till the eighth year, after which the additions are less regular. See Stages of growth of Deer.