DuckCorp Dico

Found one definition

1.                 From Japanese-English FreeDict Dictionary ver. 0.1:
                   
   
   
                   
                     
   速 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, そく /sˈo̞kɯᵝ/
   (suffix)
    (counter)
   gear, speed (e.g. 4-speed transmission)