In Oxford a contracted form of moderations. The three necessary examinations in Oxford are the Smalls, the Mods, and the Greats. No one can take a class till he has passed the Mods. There are no Mods at Cambridge.
“While I was reading for Mods I was not so unsettled in my mind.”—
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894