| Noun | 1. | alto - a singer whose voice lies in the alto clefcountertenor - a male singer with a voice above that of a tenor |
| 2. | alto - the lowest female singing voice singing voice - the musical quality of the voice while singing | |
| 3. | alto - the highest adult male singing voicesinging voice - the musical quality of the voice while singing | |
| 4. | alto - (of a musical instrument) the second highest instrument in a family of musical instruments pitch - the property of sound that varies with variation in the frequency of vibration | |
| 5. | alto - the pitch range of the lowest female voicepitch - the property of sound that varies with variation in the frequency of vibration | |
| Adj. | 1. | alto - of or being the lowest female voicelow-pitched, low - used of sounds and voices; low in pitch or frequency |
| 2. | alto - of or being the highest male voice; having a range above that of tenorhigh-pitched, high - used of sounds and voices; high in pitch or frequency | |
| 3. | alto - (of a musical instrument) second highest member of a group; "alto clarinet or recorder"music - an artistic form of auditory communication incorporating instrumental or vocal tones in a structured and continuous manner high-pitched, high - used of sounds and voices; high in pitch or frequency |