/ Dictionary / Index T trimethylglycine: Meaning and Definition of Find definitions for: tri•meth•yl•gly•cine Pronunciation: (trī-meth"ul-glī'sēn, -glī-sēn'), [key] — n. Chem. betaine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trimethylene trimetric Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language