i Register
In some senses, billy-be-damned is marked as colloquial. Watch for register when choosing this word.
intj
An expletive; damn it.
He whispered to Delilah and—as mad as blazes—the pair stared daggers at me and huffed off. They might hate each other, but Billy-be-damned, they hated me more.
adj
An expletive; accursed; damned.
He's a Billy-be-damned fool if he thinks that plan will work.
noun
An expletive.
It's as cold as Billy-be-damned out there.