1. Informal: to be or cause to be in a heightened emotional state, such as that of fear, anger, or excitement
2. a wild delusion (especially one induced by a hallucinogenic drug).
3. lose one’s nerve.
4. be overcome by a sudden fear.
agreeableness of sound; pleasing effect to the ear, especially (but not always) a pleasant sounding or harmonious combination or succession of words.
Etymology: Late Latin euphōnia < Greek euphōnía.