/ Dictionary / Index L lunar caustic: Meaning and Definition of Find definitions for: lu'nar caus'tic Pronunciation: [key] — Med., Chem. Med.,Chem. silver nitrate, AgNO, esp. in a sticklike mold, used to cauterize tissues. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lunar lunar cycle Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language