| EQUIVALENTS |
| ANCIENT CELTIC: Teutorigos |
| ANCIENT GERMANIC: Theoderich, Theodoricus, Theudoricus, Theutrich, Þiudreiks |
| DUTCH: Diederick, Diederik |
| ENGLISH: Dederick, Derek, Derick, Derrick, Deryck |
| FRENCH: Thierry |
| GERMAN: Diederich, Dietrich |
| HISTORY: Theodoric |
| WELSH: Tudor, Tudur |
|
| DIMINUTIVES AND SHORT FORMS |
| DUTCH: Dick, Diede, Dirk, Tiede, Ties |
| ENGLISH: Dirk |
| FRISIAN: Tiede |
| GERMAN: Dierk, Dirk, Thilo, Till, Tillo, Tilo |
| MEDIEVAL GERMAN: Tielo |
| VARIOUS: Thelonius |
|
| OTHER FORMS |
| AFRICAN AMERICAN: Dedrick |
| ENGLISH (BRITISH): Tel |
| ENGLISH: Teri, Terri, Terrie, Terry |
|
