Green’s Dictionary of Slang

a lame, limping person.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Hopping Giles, a jeering appellation given to any person who limps, or is lame. St. Giles was the patron saint of cripples, lepers, &c. churches dedicated to that saint, commonly stand out of a town, many of them having been chapels to hospitals.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn) 156: hopping Giles a cripple. St. Ægidius or Giles, himself similarly afflicted, was their patron saint. The ancient lazar houses were dedicated to him.
1864, 1867, 1870		Hotten Sl. Dict.
1885		Household Words 27 June 180: St. Giles is the patron saint of cripples; hence a lame person is mockingly called hopping giles [F&H].