Tone, in linguistics, a variation in the pitch of the voice while speaking. The word tone is usually applied to those languages (called tone languages) in which pitch serves to help distinguish words and grammatical categories—i.e., in which pitch characteristics are used to differentiate one word from another word that is otherwise identical in its sequence of consonants and vowels. For example, man in Mandarin Chinese may mean either “deceive” or “slow,” depending on its pitch.