Sam Hill

Etymology
No suitable person is known to be the original for this. Probably intended as a substitute for or, more fully, for "damned hell".

Noun

 * What the Sam Hill do you think you're doing?
 * Who the Sam Hill does he think he is?
 * Where in Sam Hill is that dog off to?
 * Where in Sam Hill is that dog off to?

Synonyms

 * See Thesaurus:the dickens