Green’s Dictionary of Slang

off, on one’s way; also as v.

1832		Albany Microscope (NY) 2 June n.p.: [cartoon caption] i’m o.p.h.
1838		Morning Post (Boston) 12 July 1/6: Faugh! Chips and porridge were a feast to them. Landlord, you’d better get died. Come, bucks, let’s o.p.h.
1838		N.O. Daily Picayune 14 Mar. 1/5: I’m o-p-h.
1850		N.Y. Herald 14 May 1/4: Murder and help were called; some one ran for the police; but before they came Faulkner and his associates were O P H.
1854		F. St. Clair Six Days in the Metropolis 85: I’m o-p-h tomorrow morning.
1857		Bell’s Life in Sydney 12 Dec. 3/3: The fight is consequently, for the present, o-p-p-h.
1886		Sporting Times 23 Jan. 1/1: The party is o p h off till we can get our railway fares to Salisbury Plain.
1894		S. Wales Echo 8 Dec. 4/1: ‘It’s no go this journey, and the sooner we’re o-p-h the better’.
1908		‘Doss Chiderdoss’ ‘When The Cranks Have Had Their Way’ Sporting Times 16 May 1/4: What! No billing and no cooing, no John Barleycorn, no ‘fizz,’ / No hilarity, no music, sport nor play! / Then I’m o.p.h.