1. noun /ˈhɔɹɪbl,ˈhɑɹɪbl/
a) A thing that causes horror; a terrifying thing, particularly a prospective bad consequence asserted as likely to result from an act.
Heres a carcase. I know not all that may be coming, but be it what it will, Ill go to it laughing. Such a waggish leering as lurks in all your horribles!
A lot of the possible horribles conjured up by the people objecting to this convention ignore the plain language of this treaty.
2. adjective /ˈhɔɹɪbl,ˈhɑɹɪbl/
b) Tremendously wrong or errant.
Wikipedia foundation.