Tunis UK /ˈtjuːnɪs/US /ˈtuːnəs/ noun2 •The capital city, since 1159, and largest city of Tunisia.Tunis, the capital of the above country, with a citadel of eminence, and the fortress of Goletta on the side of a canal, which is the greatest naval and military depot belonging to the bey. — 1827 •Tunis Governorate, one of the 24 governorates of Tunisia, which includes the capital.