/ Dictionary / Index M macrocyclic: Meaning and Definition of Find definitions for: mac•ro•cy•clic Pronunciation: (mak"rō-sī'klik, -sik'lik), [key] — adj. Chem. having a ring structure consisting of more than 12 atoms. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. macrocosm macrocyst Related Content Daily Word Quiz: philanthropy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language