E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
at college, is a man not salted. It was anciently a custom in the different colleges to play practical jokes on the new-comers. One of the most common was to assemble them in a room and make them deliver a speech. Those who acquitted themselves well had a cup of caudle; those who passed muster had a caudle with salt water; the rest had the salt water only. Without scanning so deeply, fresh-man may simply mean a fresh or new student. (See BEJAN.)