DuckCorp Dico

Found one definition

1.                 From Japanese-German FreeDict Dictionary ver. 0.2.0:
                   
   
   
                   
                     
   凸 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, とつ /tˈo̞tsɯᵝ/
   (adjectival nouns or quasi-adjectives (keiyodoshi))
    (nouns which may take the genitive case particle `no')
   vorstehende (f) Stirn