The crossword solution for the term Northern Irish City is Sligo, which is a five-letter word. Sligo is a city in Ireland located in the northwest of the country. It is the second largest city in the province of Connacht and the third largest city in the Republic of Ireland. The city is known for its beautiful scenery and its rich cultural heritage. Sligo is also home to a number of historical sites, including the ruins of a Norman castle and a number of ancient monuments.