Note: The trivium and quadrivium together made up the seven liberal arts. See Quadrivium.

2. (Zoöl.)

Defn: The three anterior ambulacra of echinoderms, collectively.

TRIWEEKLY
Tri"week`ly, a. Etym: [Pref. tri- + weekly.]

Defn: Occurring or appearing three times a week; thriceweekly; as, a triweekly newspaper. — adv.

Defn: Three times a week. — n.

Defn: A triweekly publication.

Note: This is a convenient word, but is not legitimately formed. It should mean occurring once in three weeks, as triennial means once in three years. Cf. Biweekly.

TROAD
Troad, n.

Defn: See Trode. [Obs.]