sinistrously /ˈsɪnɪstɹəsli/ adverb2 •(no longer used) In a sinistrous manner; perversely; wrongly; unluckily or sinisterly. •(no longer used) With a tendency to use the left hand.Many, in their infancy, are sinistrously disposed, and divers continue all their life left-handed. — 1646 formsmore sinistrously · most sinistrously