>I propose that we create a new word ...
Interesting debate and completely alien to me.
We have a rather quaint way of naming people at university.
People in their first year are called - First Years
People in their second year are called - Second Years
People in their third year are called - Third Years
No problem with gender differences there.
During the week at my university (and I assume, others) there was a "Freshers Fair" where those new to the university, Freshers, could go along and select clubs or activities to join. I started in 1978 and I cannot recall ever having heard the word "Freshman", so it either died out years ago or was never used. I don't think we were called Freshers for more than the first few weeks, after that were just called first years. I have only come across Sophomore in films and was never really sure which period of time it related to.
So the short answer is you don't need to study Greek to replace "Freshman" you could call people "Freshers", "First Years" or perhaps even ......."Newbies"