improper
1 impolite, indecent, indecorous, indelicate, off-colour, risqué, smutty, suggestive, unbecoming, unfitting, unseemly, untoward, vulgar
2 ill-timed, inapplicable, inapposite, inappropriate, inapt, incongruous, infelicitous, inopportune, malapropos, out of place, uncalled-for, unfit, unseasonable, unsuitable, unsuited, unwarranted
3 abnormal, erroneous, false, inaccurate, incorrect, irregular, wrong
Antonyms
1 becoming, decent, decorous, delicate, fitting, proper, seemly
2 apposite, appropriate, apt, felicitous, opportune, seasoned, suitable