Green’s Dictionary of Slang

fresher n.

also fresh, freshie
[SE freshman; one of the last survivors of the -er sfx, which once offered ‘Pragger Wagger’, the Prince of Wales, ‘wagger pagger bagger’, waste paper basket etc.]

1. [late 19C+] (UK/US campus) a student in their first term at a university.

2. [1910s] a new arrival among a group of soldiers.