1. A quantity which can not be expressed by rational numbers; thus, *2 is a surd.

2. (Phon.)

Defn: A surd element of speech. See Surd, a., 4.

SURDAL
Surd"al, a. (Math.)

Defn: Same as Surd, a., 3.

SURDINY
Surd"i*ny, n.

Defn: A sardine. [Obs.] Beau. & Fl.

SURDITY
Surd"i*ty, n. Etym: [L. surditas.]

Defn: Deafness. [Obs.]

SURE
Sure, a. [Compar. Surer; superl. Surest.] Etym: [OE. sur, OF. seür,
F. sûr, L. securus; se aside, without + cura care. See Secure, and
cf. Assure, Insure, Sicker sure.]