DuckCorp Dico

Found one definition

1.                 From Mueller English-Russian Dictionary:
                   
   
   
                   
                     
   cotter
      _I  [↗kɘtɜ] = cottar
      II [↗kɘtɜ] n. _тех.
         1) клин, чекА, шпОнка
         2) _attr. cotter bolt болт с чекОй