An Etymological Dictionary of the German Language/Essig
Essig, m. (with the normal unaccented g for ch), ‘vinegar,’ from the equiv. MidHG. ęȥȥī̆ch (that the i is long is proved by its change into the diphthong ei in late MidHG. ezseich), OHG. ęȥȥîh (hh), m. A remarkable loan-word, corresponding to MidLG. ętik, OSwed. œtikia, Swed. ättika; also OLG. ęcid, AS. ęced, which with Goth. akeit(s), ‘vinegar,’ are based upon Lat. acêtum. For the HG., LG., and Swed. words we must assume a form *atêcum, produced by metathesis of the consonants — OHG. ęȥȥîh from atîk for atêko, which, however, is not attested by any Romance form; for such transpositions comp. Romance alenâre from Lat. anhelare, MidHG. biever from vieber (see further citations under einzeln, Fieber, Erle, Kabeljau, kitzeln, Ziege). There is a remarkable form in Swiss dialects, achiss, echiss, which is based upon an untransposed form corresponding to Goth. akeit(s). The Lat.-Rom. acêtum (Ital. aceto; but Fr. vinaigre and E. vinegar from Lat. vinum acre) has also made its way into other countries — OSlov. acǐtŭ (from Goth. akeits?), OIr. acat. — The UpG. vb. esseln, ‘to taste of vinegar,’ may perhaps be based upon some such form as OFr. aisil (MidE. aisil).