Jesus H. Christ is an example of slang serving as a profanity.[1]
The expression dates to at least the late 19th century, although according to Mark Twain it was already old in 1850.[2]
Using the name of Jesus Christ as an oath has been common for many centuries, but the precise origins of the letter H in the expression Jesus H. Christ are obscure. While many explanations have been proposed, some serious and some not, the most widely accepted derivation is from the divine monogram of Christian symbolism. The symbol, derived from the first three letters of the Greek name of Jesus (Ιησούς), is transliterated iota-eta-sigma: IHS, ΙΗϹ (with lunate sigma), JHS or JHC. Since the transliteration IHS gave rise to the backronym Iesus Hominum Salvator (Latin for "Jesus, savior of men"), it is plausible that JHC similarly led to Jesus Harnaldo Christ,[3] Harold coming from the mispronunciation of the word "hallowed" of the Lord's Prayer: "Our Father who art in heaven hallowed be thy name." The H has also been said to stand for "Holy."