An Etymological Dictionary of the German Language/Annotated/Wachholder
Wachholder, masculine, ‘juniper, gin’; the word has attained its present form by many inorganic changes; it is based on the equivalent Old High German wëhhalturia (Middle High German wëcheltürre) and wëhhœltar (Middle High German wëcholter); in Middle High German also wachalter, quëckolter, rëckholter in represented by the modern Alemannian form Reckholder). Holunder and Maßholder show that the derivative syllable is MidHigh German -ter; as in the case of Maßholder, the final syllables were changed to Holder, equivalent to Holunder. The signification of the l derivative, Old High German *wëhhal, ‘juniper’ (also wëhhan- in dialectic Wachandel), is entirety inexplicable.