An Etymological Dictionary of the German Language/Annotated/zittern

by Friedrich Kluge

zittern, verb, ‘to tremble, shake, quiver,’ from the equivalent Middle High German zitern, zittern, Old High German zittarôn, weak verb; corresponding to Old Icelandic titra, ‘to twinkle, wink, tremble’ (old tr remains unpermutated in High German; compare bitter, Splitter, and treu). Zittern is one of the few Teutonic verbs which have a reduplicated present (see beben). From the implied primitively Teutonic *ti-trô-mi the transition to the weak ô conjugation is easily understood, just as the change of Teutonic *rî-rai-mi, ‘I tremble’ (compare Gothic reiran, ‘to shake,’ from an Aryan root rai-), to the similarly sounding weak ai conjugation. In the non-Teutonic languages no cognates of zittern have been found (Aryan root drā̆?). The German word was adopted by Danish; compare Danish zittre, ‘to shake.’