A*ton"ic (&?;), a. [Cf. F. atonique. See Atony.] 1. (Med.) Characterized by atony, or want of vital energy; as, an atonic disease.

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

3. Destitute of tone vocality; surd. Rush.

A*ton"ic, n. 1. (Gram.) A word that has no accent.

2. An element of speech entirely destitute of vocality, or produced by the breath alone; a nonvocal or surd consonant; a breathing. Rush.

3. (Med.) A remedy capable of allaying organic excitement or irritation. Dunglison.

• Referring to a syllable or sound that is spoken without accent or stress.
  
• (pathology) Lacking muscle tone.