WordNet sense 1 (used of persons or their behavior):

impossible, insufferable, unsufferable

WordNet sense 2 (incapable of being put up with):

intolerable

WordNet sense 3 (not conforming to standard usage):

unaccepted

WordNet sense 4 (not conforming to the language usage of a prestige group within a community):

nonstandard

WordNet sense 5 (not giving satisfaction):

unsatisfactory