Atonic

Part of speech: noun (n.)

1. 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. A remedy capable of allaying organic excitement or irritation. Dunglison.

Part of speech: adjective (a.)

1. Characterized by atony, or want of vital energy; as, an atonic disease.

2. Unaccented; as, an atonic syllable.

3. Destitute of tone vocality; surd. Rush.