, Old High German diota, Middle High German diet, Old Norse þióð, Gothic þiuda < Old Germanic *þeuđô, by Verner's Law < Indo-European *teut- feminine; compare Lithuanian tautà, Old Irish túath, Oscan touto, Sabine touta people. Old English þíod, þéod = Old Saxon thioda, thiod, Old Frisian thiade(The character coming out is probably meant to be ā́, I should think. The online OED3 is still having a lot of encoding problems.)
There are possibly some even more savory cognates to be added to the OED etymology— such as Latin tōtus, "the whole of, all," if originally *"all of the tribe". This derivation is suggested by the that fact that although Oscan has touto and Sabine touta, "people," a cognate is missing in their sister Italic language Latin, unless it be tōtus. Even more interesting as possible cognates are Hittite tuzzi "army; camp" and Lycian tuta "army." However, Benveniste in particular rejected the association of the family of thede with the Anatolian forms, but other authors have accepted it. If consensus on this question has been reached I am not aware of it. Of particular interest, whatever its further intrafamilial relations, is the possibility that Hittite tuzzi is the source of Old Assyrian tuzinnum, some sort of land division to which were certain feudal military obligations were attached. A brief synopsis of the problem by V. Ivanov is here:
http://www.humnet.ucla.edu/pies/pdfs/iec/iec19/ivanov_v_2007f.pdf. In this way, along with the reflexes of Hittite išḫiul, "contract," also found in the Old Assyrian texts, tuzzi may be one of the oldest attested Indo-European words. The contracts had enforcers.