1. (Gram.)

Defn: 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.)

Defn: A remedy capable of allaying organic excitement or irritation.
Dunglison.

ATONY
At"o*ny, n. Etym: [Gr. atonie.] (Med.)

Defn: Want of tone; weakness of the system, or of any organ, especially of such as are contractile.

ATOP
A*top", adv.

Defn: On or at the top. Milton.

ATRABILARIAN; ATRABILARIOUS At`ra*bi*la"ri*an, At`ra*bi*la"ri*ous, a. Etym: [LL. atrabilarius, fr. L. atra bilis black bile: cf. F. atrabilaire, fr. atrabile.]