/ Dictionary / Index N Northumberland Strait: Meaning and Definition of Find definitions for: Northum'berland Strait' Pronunciation: [key] the part of the Gulf of St. Lawrence that separates Prince Edward Island from New Brunswick and Nova Scotia, in SE Canada. ab. 200 mi. (320 km) long; 9–30 mi. (15–48 km) wide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Northumberland Northumbria 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