/ Dictionary / Index B betulaceous: Meaning and Definition of Find definitions for: bet•u•la•ceous Pronunciation: (bech"oo-lā'shus), [key] — adj. belonging to the Betulaceae, the birch family of plants. Cf. birch family. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: betulaceous (Thesaurus) Betty lamp betula oil Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language