/ Dictionary / Index S secondly: Meaning and Definition of Find definitions for: sec•ond•ly Pronunciation: (sek'und-lē), [key] — adv. in the second place; second. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: secondly (Thesaurus) second lieutenant second mate Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language