not hallowed or consecrated
extremely evil or cruel; expressive of cruelty or befitting hell
"something demonic in him--something that could be cruel"
"fires lit up a diabolic scene"
"diabolical sorcerers under the influence of devils"
"a fiendish despot"
"hellish torture"
"infernal instruments of war"
"satanic cruelty"
"unholy grimaces"
Not holy; (by extension) evil, impure, or otherwise perverted.
Unholy comes from Middle English and Old English, where it meant "not holy." It is formed by adding the prefix un- to the word holy.