unbecoming

/ˌən-bi-ˈkə-miŋ/

adjective

  1. not becoming; especially : not according with the standards appropriate to one's position or condition of life

an unbecoming dress

indecorous improper unseemly unbecoming indelicate mean not conforming to what is accepted as right, fitting, or in good taste. indecorous suggests a violation of accepted standards of good manners. improper applies to a broader range of transgressions of rules not only of social behavior but of ethical practice or logical procedure or prescribed method.