Closely associated or paired with something else, often in a way that is complementary or similar. The twinned cities have a strong cultural exchange program.
Consisting of two identical or similar parts. The twinned towers were a prominent feature of the city's skyline.
Having a twin or being one of a pair of twins. The twinned siblings were inseparable throughout their childhood.
In crystallography, formed of two or more crystals that have grown together in a symmetrical fashion. Under the microscope, the mineral appeared as a cluster of finely twinned crystals.