WordWeb Online

1. Not in keeping with accepted standards of what is right or proper in polite society
   "moved to curb their untoward ribaldry";
   - indecent, indecorous, unbecoming, uncomely, unseemly
    
2. Contrary to your interests or welfare
   "made a place for themselves under the most untoward conditions";
   - adverse, inauspicious

See also: improper, unfavorable [US], unfavourable [Brit, Cdn]

Encyclopedia: Untoward