• (a.) Destitute of virtue; without efficacy or operating qualities; powerless.
Vir'tue·less adjective Destitute of virtue; without efficacy or operating qualities; powerless. « Virtueless she wished all herbs and charms.» Fairfax. 
virtueless 1. Destitute of efficacy or excellence; ineffective, worthless. 2. Destitute of virtue or moral goodness; immoral, vicious.