An Etymological Dictionary of the German Language/Annotated/zag
zag, adjective ‘faint-hearted, shy, irresolute,’ from Middle High German zage, Old High German zago, zag, adjective, ‘faint-hearted, cowardly.’ A derivative of Modern High German zagen, ‘to lack courage, hesitate’ (compare wach and wachen), Middle High German zagen, Old High German zagên. It is not probable that the word was borrowed, in spite of the few cognates of the Teutonic stem tag. This is probably derived from a Gothic *at-agan (1st singular *ataga, equivalent to Irish ad-agur, ‘to be afraid’) by apocope of the initial vowel; at is probably a prefix Gothic agan, ‘I am afraid,’ is based on the widely diffused Old Teutonic root ag (Aryan agh), ‘to be afraid,’ with which Greek ἄχος, ‘pain, distress,’ is also connected.