her ‧ e ‧ sy /ˈherəsi, ˈherɪsi/ BrE AmE noun ( plural heresies ) [uncountable and countable]
[ Date: 1100-1200 ; Language: Old French ; Origin: heresie , from Late Latin haeresis , from Greek hairesis 'act of taking or choosing' ]
1 . a belief that disagrees with the official principles of a particular religion:
He was executed for heresy.
2 . a belief, statement etc that disagrees with what a group of people believe to be right:
To come to work without a shirt and tie was considered heresy.