/ Dictionary / Index F frostline: Meaning and Definition of Find definitions for: frost•line Pronunciation: (frôst'līn", frost'-), [key] — n. the maximum depth at which soil is frozen. the lower limit of permafrost. Cf. permafrost table. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. frosting frost point Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language