Delhi /ˈdɛl.i/noun 1phrases 1 noun1 •A megacity and union territory of India, containing the national capital New Delhi.The £4bn expressways form a diamond linking Delhi with the country's three other largest cities, Mumbai, Chennai and Calcutta, marking the beginning of more than £35bn of road projects. — 2007 Phrases with Delhi Delhi bellyDigestive illness or diarrhea, especially if suffered by a visitor to India.