Student or Learner
What is this expression equivalent to?
Is this very literary? archaic?
I'm not sure that it really is an expression; we have 'in detachment' but the verb can change. I can't see any particular features of it that would make it literary. The concept of detachment from the distractions of life is certainly very old and lies behind monasteries, etc, but I'm not sure that it's archaic; just not very common.