/ Dictionary / Index P portal circulation: Meaning and Definition of Find definitions for: por'tal circula'tion Pronunciation: [key] — Physiol. Physiol. blood flow in a portal system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Port Alberni portal system Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language