An etymological explanation or rare dictionary meaning may be a valid scholarly achievement. It does not follow that the original audience could immediately recognize the intended meaning without such help.
In the discussion of musarrajan, competing interpretations expose precisely this distinction. “A plausible sense can be reconstructed” is not identical to “the sense is apparent in ordinary use.”
Thus distinguish lexical legitimacy, common familiarity, and contextual intent when evaluating a difficult expression.