Synonyms of unallowable

2 Syllables

inapt, inept, unfit

3 Syllables

improper, ill-timed, unsuited, unseemly, unwanted

4 Syllables

irrelevant, unqualified, unwelcome, unbecoming, malapropos, ill-favored, immaterial, incompetent

5 Syllables

unreasonable, inexcusable, undesirable, objectionable, inadmissible, inappropriate, unforgivable, criticizable, unpermissible, unacceptable, exceptionable

6 Syllables

unsatisfactory