1. A goldsmith's tool used in making rings. Ainsworth.

2. A steel cylinder round which metal is drawn in the process of forming tubes. Tomlinson.

3. (Blacksmithing)

Defn: A tapering mandrel.

TRIBOMETER
Tri*bom"e*ter, n. Etym: [Gr. -meter: cf. F. tribomètre.]

Defn: An instrument to ascertain the degree of friction in rubbing surfaces. Brande & C.

TRIBRACH
Tri"brach, n. Etym: [L. tribrachys, Gr. Tri-) + (Gr. & L. Pros.)

Defn: A poetic foot of three short syllables, as, mèlì\'dcs.

TRIBRACTEATE
Tri*brac"te*ate, a. Etym: [Pref. tri- + bracteate.] (Bot.)

Defn: Having three bracts.