/ Dictionary / Index S seminal: Meaning and Definition of Find definitions for: sem•i•nal Pronunciation: (sem'u-nl), [key] — adj. pertaining to, containing, or consisting of semen. of or pertaining to seed. having possibilities of future development. highly original and influencing the development of future events: a seminal artist; seminal ideas. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seminal (Thesaurus) semimonthly seminal fluid Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language