Easton's Bible Dictionary
Trumpets were at first horns perforated at the tip, used for various purposes (Joshua 6:4, 5).
But the word is used also metaphorically to denote the projecting corners of the altar of burnt offerings (Exodus 27:2) and of incense (30:2). The horns of the altar of burnt offerings were to be smeared with the blood of the slain bullock (29:12; Leviticus 4:7-18). The criminal, when his crime was accidental, found an asylum by laying hold of the horns of the altar (1 Kings 1:50; 2:28).
The word also denotes the peak or summit of a hill (Isaiah 5:1, where the word "hill" is the rendering of the same Hebrew word).
This word is used metaphorically also for strength (Deuteronomy 33:17) and honour (Job 16:15; Lamentations 2:3). Horns are emblems of power, dominion, glory, and fierceness, as they are the chief means of attack and defence with the animals endowed with them (Dan. 8:5, 9; 1 Samuel 2:1; 16:1, 13; 1 Kings 1:39; 22:11; Joshua 6:4, 5; Psalm 75:5, 10; 132:17; Luke 1:69, etc.). The expression "horn of salvation," applied to Christ, means a salvation of strength, or a strong Saviour (Luke 1:69). To have the horn "exalted" denotes prosperity and triumph (Psalm 89:17, 24). To "lift up" the horn is to act proudly (Zechariah 1:21).
Noah Webster's New International Dictionary of the English Language
1. (n.) A hard, projecting, and usually pointed organ, growing upon the heads of certain animals, esp. of the ruminants, as cattle, goats, and the like. The hollow horns of the Ox family consist externally of true horn, and are never shed.
2. (n.) The antler of a deer, which is of bone throughout, and annually shed and renewed.
3. (n.) Any natural projection or excrescence from an animal, resembling or thought to resemble a horn in substance or form; esp.: (a) A projection from the beak of a bird, as in the hornbill. (b) A tuft of feathers on the head of a bird, as in the horned owl. (c) A hornlike projection from the head or thorax of an insect, or the head of a reptile, or fish. (d) A sharp spine in front of the fins of a fish, as in the horned pout.
4. (n.) An incurved, tapering and pointed appendage found in the flowers of the milkweed (Asclepias).
5. (n.) Something made of a horn, or in resemblance of a horn
6. (n.) A wind instrument of music; originally, one made of a horn (of an ox or a ram); now applied to various elaborately wrought instruments of brass or other metal, resembling a horn in shape.
7. (n.) A drinking cup, or beaker, as having been originally made of the horns of cattle.
8. (n.) The cornucopia, or horn of plenty.
9. (n.) A vessel made of a horn; esp., one designed for containing powder; anciently, a small vessel for carrying liquids.
10. (n.) The pointed beak of an anvil.
11. (n.) The high pommel of a saddle; also, either of the projections on a lady's saddle for supporting the leg.
12. (n.) The Ionic volute.
13. (n.) The outer end of a crosstree; also, one of the projections forming the jaws of a gaff, boom, etc.
14. (n.) A curved projection on the fore part of a plane.
15. (n.) One of the projections at the four corners of the Jewish altar of burnt offering.
16. (n.) One of the curved ends of a crescent; esp., an extremity or cusp of the moon when crescent-shaped.
17. (n.) The curving extremity of the wing of an army or of a squadron drawn up in a crescent like form.
18. (n.) The tough, fibrous material of which true horns are composed, being, in the Ox family, chiefly albuminous, with some phosphate of lime; also, any similar substance, as that which forms the hoof crust of horses, sheep, and cattle; as, a spoon of horn.
19. (n.) A symbol of strength, power, glory, exaltation, or pride.
20. (n.) An emblem of a cuckold; -- used chiefly in the plural.
21. (v. t.) To furnish with horns; to give the shape of a horn to.
22. (v. t.) To cause to wear horns; to cuckold.