Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The horn in a dream is a man's strength, his defense, and his weapon. The strength of the horns indicates the strength of the ruler. A broken horn indicates the loss of position or humiliation.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The horn indicates a year, a son, or wealth. Whoever sees that he has horns like a bull's horns will gain authority and prestige.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The horn is interpreted as strength and defense. Whoever sees an animal strike him with its horn will be harmed by a strong man.