Defn: A tunicate.
TETHYODEA
Te`thy*o"de*a, n. pl. Etym: [NL., fr. Tethys + Gr. (Zoöl.)
Defn: A division of Tunicata including the common attached ascidians, both simple and compound. Called also Tethioidea.
TETHYS
Te"thys, n. Etym: [NL., fr. Gr. (Zoöl.)
Defn: A genus of a large naked mollusks having a very large, broad, fringed cephalic disk, and branched dorsal gills. Some of the species become a foot long and are brilliantly colored.
TETRA-
Tet"ra-. Etym: [Gr. Four.]
1. A combining form or prefix signifying four, as in tetrabasic, tetrapetalous.
2. (Chem.)
Defn: A combining form (also used adjectively) denoting four proportional or combining parts of the substance or ingredient denoted by the term to which it is prefixed, as in tetra-chloride, tetroxide.
TETRABASIC
Tet`ra*bas"ic, a. Etym: [Tetra- + basic.] (Chem.)