bomb·shell /ˈbɑ:mˌʃɛl/ noun plural bomb·shells
] 1 :
something that is very surprising or shocking — usually singular ▪ The book was a political bombshell. ▪ The news of his departure was a bombshell. ▪ She dropped a bombshell [=she surprised everyone] when she said she wouldn't run for reelection.
2 informal :
a very attractive woman — usually used in the phrase blond/blonde bombshell to refer to an attractive woman with blonde hair ▪ She's a blonde bombshell who looks like a movie star of the 1950s.