Green’s Dictionary of Slang

(US campus) to use any form of translation as an aid to work.

1847		in W.G. Hammond Remembrance of Amherst (1946) 153: Not one Psi U has yet carried in his book on conics; while the others are ponying most unmercifully .
1856		B.H. Hall College Words (rev. edn) 358: pony. To use a translation.
1871		L.H. Bagg Four Years at Yale 46: Pony, [...] As a verb, to make use of such translations in reading out a lesson.
1896		W.C. Gore Student Sl. in Cohen (1997) 11: pony Same as ‘horse’ [...] To make use of illegitimate help, as by translations, keys, etc.
1908		W.G. Davenport Butte and Montana beneath the X-Ray 134: It were a hundred times better to teach the average boy how to build a fence, [...] dress a beef or re-sole a pair of shoes than to read Euripides or ‘pony’ his way through three or four years of Latin [DA].