wham ‧ my /ˈwæmi/ BrE AmE noun [singular] informal
[ Date: 1900-2000 ; Origin: Probably from wham ]
1 . double/triple whammy two or three unpleasant things that happen at or around the same time and cause problems or difficulties for someone or for people in general:
The government’s policy is higher tax and higher interest rates. It’s a double whammy.
2 . put the whammy on somebody American English to use magic to make someone have bad luck