Green’s Dictionary of Slang

1. a lame person; often as a nickname.

1841		‘Nothing Like Pride About Me’ Dublin Comic Songster 256: I vonce doffed my holiday togs, [...] And had a coat fronted with frogs, / A vestcoat and brichis by Stultz; / Vhile giving Lord Hoppy a call.
1858		Leics. Mercury 23 Oct. 8/2: Thomas, alias ‘Hoppy Berridge‘, remanded on a charge of passing a counterfeit florin.
1881		Exeter & Plymouth Gaz. 16 Nov. 4/1: A betting man known as ‘Hoppy’, an appellation applied to him because he is lame.
[1892		Brooklyn Dly Eagle (NY) 4 Dec. 3/7: Hoptygofetchit [...] was sitting with his lame foot up on the [...] stove].
1893		P.H. Emerson Signor Lippo 90: He and them two luck-go-’oppies, they used to be on at a ’all, but then they took up the needy lay.
1902		in J. Wright EDD (1905) III 232/2: Among the working classes, lame persons are often nicknamed ‘Oppy’, as ‘Oppy Smith’, which denotes a certain Smith who is somewhat lame.
1904		Number 1500 Life In Sing Sing 249: Hoppy. A cripple.
1914		Joyce ‘A Mother’ Dubliners (1956) 134: He had a game leg, and for this his friends called him Hoppy Holohan.
1949		Monteleone Criminal Sl. (rev. edn).
1953		J. Franklyn Cockney 275: A person walking with a limp is addressed as ‘Hoppy’ [...] ‘Hoppy-foot-Jack’, or ‘Hoppy-leg-Harry’.
1991		R.G. Barrett Between the Devlin 38: ‘That’s why the limp. And why they call me Hoppy’.
1994		(con. 1930s) K.C. Kearns Dublin Tenement Life 97: There was a man and he used to have a short leg and we used to call him ‘Hoppy’ Gaynor.

2. a flea; usu. in pl.

1980

Barltrop & Wolveridge Muvver Tongue 32: There is no rhyming word for fleas; they are usually called ‘hoppies’.