amazed   astonished    (to be) gushirwa, gutangāra
En-En dictionary 
gutangāra (-tangāye)     v    to marvel, to be astonished, to be amazed, to be astounded
gutangāzwa (-tangājwe)     v    to be amazed, astounded
 amazed found in: Kirundi II (Grammar)
chapter 39   –tuma used to show Reason or Cause