/ Dictionary / Index S sea pen: Meaning and Definition of Find definitions for: sea' pen" Pronunciation: [key] any of several colonial coelenterates of the genus Pennatula and related genera, having the shape of a fleshy feather. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sea palm seaperch Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language