Found one definition

  1.                 From Japanese-German FreeDict Dictionary ver. 0.2.0:
                    

    (ateji (phonetic) reading) 治具, (ateji (phonetic) reading) (word containing irregular kanji usage) 冶具, じぐ, () ジグ (noun (common) (futsuumeishi))

    Note: word usually written using kana alone(1) (f) Einspannvorrichtung, (f) Spannvorrichtung, (2) (n) Jig (Köderart)