DuckCorp Dico

Found one definition

1.                 From English-日本語 (にほんご) FreeDict+WikDict dictionary ver. 2022.11.18:
                   
   
   
                   
                     
   stun //stʌn// <v>
   1. 気絶
   to incapacitate
   2. 呆然
   to shock or surprise