SHANKS'S PONY Meaning of SHANKS'S PONY in English ( N. Amer. also Shanks's mare ) ■ noun one's own legs as a means of conveyance.OriginC18: first recorded as shanks-nag in R. Fergusson's Poems (1785). Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004