/ Dictionary / Index T testaceous: Meaning and Definition of Find definitions for: tes•ta•ceous Pronunciation: (te-stā'shus), [key] — adj. of, pertaining to, or derived from shells. having a test or shell-like covering. of a brick-red, brownish-red, or brownish-yellow color. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: testaceous (Thesaurus) testacean test act Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language