- indecent, indecorous, unbecoming, uncomely, unseemly, untoward - not in keeping with accepted standards of what is right or proper in polite society; "was buried with indecent haste"; "indecorous behavior"; "language unbecoming to a lady"; "unseemly to use profanity"; "moved to curb their untoward ribaldry"
Antonym: proper (indirect, via improper)