Green’s Dictionary of Slang

unintelligible language.

1599		Greene George-A-Greene D1: grime: Are you not some craftie queane, That comes from George a Greene, that rascall, With some letters to my daughter? [...] wily: Alas, sir, it is Hebrue vunto me].
1680		School of Venus (2004) 9: This discourse is Hebrew to me.
1705		Vanbrugh Confederacy II i: mon.: If she did but know what part I take in her Sufferings. flip.: Mighty obscure. mon.: Well, I’ll say no more; but —flip.: All Hebrew.
1821		‘An Amateur’ Real Life in London I 45: This narrative of Hairbrain was like Hebrew to Tallyho, who requested his interesting cousin, as he found himself at falt, to try back, and put him on the right scent.
1839		N.O. Picayune 1 Mar. 2/4: Even admitting a person understands French and pronounces the name of a dish correctly, its all Hebrew or Choctaw to the waiter [DA].
1843		R.S. Surtees Handley Cross (1854) 303: His opinions [...] being Hebrew to Mrs Muleygrubs, and very nearly Hebrew to her husband.
1862		Golden Age (Queanbeyan, NSW) 4 Sept. 3/2: Tom’s fistic slang is like so much Hebrew to us .
1890		Sporting Times 22 Mar. 2/1: ‘Ou ai,’ she could cook it. ‘An’ would ye like some tatties ’n things?’ ‘Ou ai,’ I said, as that seemed to be the prevailing Hebrew of the country.