1. (a.) Characterized by want of vital energy; as, an atonic disease.

2. (a.) Unaccented; as, an atonic syllable.

3. (a.) Destitute of tone vocality; surd.

4. (n.) A word that has no accent.

5. (n.) An element of speech entirely destitute of vocality, or produced by the breath alone; a nonvocal or surd consonant; a breathing.

6. (n.) A remedy capable of allaying organic excitement or irritation.