WordNet sense 1 (not having a coating of stain or varnish):

unvarnished

WordNet sense 2 (not having a coat of paint or badly in need of a fresh coat):

unpainted

WordNet sense 3 (without soil or spot or stain):

unsoiled, unspotted

WordNet sense 4 (free from dirt or impurities; or having clean habits):

clean

WordNet sense 5 (of reputation):

stainless, unsullied, untainted, untarnished

WordNet sense 6 (free from physical or moral spots or stains):

unblemished