/ Dictionary / Index F first baseman: Meaning and Definition of Find definitions for: first' base'man Pronunciation: [key] — Baseball. Baseball. the player whose position is first base. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. first base firstborn Related Content Daily Word Quiz: verdant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language