Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
stun [stʌn] vt (subj, news) ошеломля́ть (ошеломи́ть*perf) (:blow on head) оглуша́ть (оглуши́ть perf)
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: