Both Dietrich and Dieter are similar in sound, but slightly different etymologically, now considered dated in their home country of Germany, as well as in Austria and Switzerland, Dieter (DEE-ter) is derived from the Old Germanic elements theud meaning “people” and hari meaning “army.” While Dietrich (DEET-reekh) is a derivative of the ancient Germanic Theodoric, which is derived from the elements theud, (again, meaning people), and ric meaning, “power; ruler.”
Derek is a low Germanic form of Dietrich. Derek became quite prevalent in the United States circa the late 1960s, he currently comes in at #159.
Dirk is also an offshoot, being a Dutch diminutive form. This particular form was introduced into the English speaking world by actor Dirk Bogarde, (1921-1999). In the United States, Dirk is not as popular as Derek. The last he was seen was back in 1989 coming in at #993.
Then there is the simpler version of Till, which is currently very popular in Germany and other Germanic countries, it is an off shoot of the old Low German name, Tielo, which is a variation of Diede, a diminutive form of Diederich. The name was borne by a 7th-century Saxon saint, who was kidnapped and taken hostage Saxony, after his release, he became a Benedictine monk.
The popular French male name, Thierry, is also a distant relation of Diedrich. The name was borne in the early middle ages by Theodoric, King of the Ostrogoths, who eventually became King of Italy. In Germany, Dieter and Dietrich’s designated name days are September 7th.
Other forms of the name include:
- Theoderich (Ancient Germanic)
- Diede (Dutch: initially a diminutive form, used as an independent given name; DEE-de)
- Diederick/Diederik (Dutch)
- Thierry (French)
- Thiadrick (Frisian: older form)
- Tiede (Frisian: TEE-de)
- Tiark/Tjark/Tjerk (Frisian: TYARK/TYERK)
- Diederich (German: archaic and obscure)
- Dierk (German)
- Dietreich (German: obscure)
- Dirich (German: Northern dialectical form, archaic)
- Till/Til (German: modern form of Tielo, the name is currently very trendy in German speaking countries)
- Tillo (German)
- Detrik (Hungarian)
- Theodoricus/Theudoricus (Latin)
- Ditericus (Latin)
- Dieterik (Low Saxon)
- Tielo (Low Saxon)
- Didrik (Swedish)
- Tudor/Tudur (Welsh)
Some Germanic diminutive forms are: Dietz, Dedo/Deddo, Derk, Diedo, Didi and Diet.
Feminine versions are:
- Dietke (Dutch: DEET-ke)
- Tiada/Tjada/Tjadina (Frisian)
- Tjalda/Tialda (Frisian)
- Dieta/Dita/Didda (German)
- Dietra (German: obscure)
- Tilina (German)
- Tilla (German: also used as a contraction for Otilia and Matilda).