/ Dictionary / Index I Il Penseroso*: Meaning and Definition of Find definitions for: Il Pen•se•ro•so Pronunciation: (il pen"su-rō'sōIt.ēl pen'se-rô'sô), [key] a poem (1632) by John Milton. Cf. L'Allegro. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. I.L.P. ILS Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language