twin town

noun

British a town that has civic associations, such as reciprocal visits and cultural exchanges, with a foreign town, usually of similar size and sometimes with other similarities, as in commercial activities

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for twin town

Historical Examples of twin town

Not very far above the bridge the river bifurcates, the two branches being east and west to match the twin-town.
Cornwall
G. E. Mitton