Jesus-h-christ definition

Extension of Jesus Christ with a fantastical middle initial, perhaps derived from a reading of ΙΗΣ (IĒS), a Greek-alphabet abbreviation for Jesus (ΙΗΣΟΥΣ) as three initials in Latin letters. See "Christogram" at Wikipedia.

The expression dates to at least the late 19th century (although according to Mark Twain, it was already old in 1850) (Smith 1994, p. 332).