/ Dictionary / Index T tree fern: Meaning and Definition of Find definitions for: tree' fern" Pronunciation: [key] any of various ferns, mostly tropical and chiefly of the family Cyatheaceae, that attain the size of trees, sending up a straight trunklike stem with foliage at the summit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tree farm treefish Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language