Synonyms for Unfit (same or very similar meaning)
WordNet sense 1 (physically unsound or diseased):
bad, unsoundWordNet sense 2 (not in or exhibiting good health in body or mind):
unhealthyWordNet sense 3 (not meant or adapted for a particular purpose):
unsuitableWordNet sense 4 (make unfit or unsuitable):
disqualify, indisposeFrom the ODE community, based on WordNetadd/edit