DuckCorp Dico

Found one definition

1.                 From Japanese-English FreeDict Dictionary ver. 0.1:
                   
   
   
                   
                     
   音引き /(en)tʃˈaɪniːz(ja)lˈe̞tə (en)tʃˈaɪniːz(ja)lˈe̞tə kˈi/, おんびき /ˌo̞ũbˈiki/
   1. (noun (common) (futsuumeishi))
   looking up a word or kanji by its reading (rather than by its radical or stroke count)
   2. 長音符・ちょうおんぷ
            Note: colloquialismkatakana-hiragana prolonged sound mark