As adjectives the difference between simple and nondescript
is that
simple is uncomplicated; taken by itself, with nothing added while
nondescript is not described (in the academic literature); undescribed, unidentified.
As nouns the difference between simple and nondescript
is that
simple is (medicine) a preparation made from one plant, as opposed to something made from more than one plant while
nondescript is an undistinguished, unexceptional person or thing.
As a verb simple
is (transitive|intransitive|archaic) to gather simples, ie, medicinal herbs.