The name 'Radyk' is a diminutive variant with the suffix -ik derived from the names Rad, Rady, or Radyō. It is first mentioned in Ukraine in 1565, in the records of Iwan Radik and the serf Iwan Radik from Bar. Similar formations are recorded among Poles since the 13th century. For instance, in a record from 1265, the name Christina et Radie is found. There is also a related patronymic surname of the Cossack from the Bracław regiment, Fedir Radyechenko, which dates back to 1649.
