/ Dictionary / Index S sun letter: Meaning and Definition of Find definitions for: sun' let"ter Pronunciation: [key] — Arabic Gram. Arabic Gram. any letter, as tā or sīn, representing a consonant that assimilates the l of a prefixed definite article. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sunless sunlight Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language