Not a word, but a phrase
We are sorry to inform you..............I know that I do NOT want to hear the words that come after that phrase.
Pregnant...may that never be!!
Nasty. A nurse said that word to me as a kid when I was getting chemotherapy, and has freaked me out ever since.
Its a tie between Bl_od_ M_ry or Can_y M_n!
The C-bomb, for the social entropy it represents.