adv. 1. In a sinistrous manner; perversely; wrongly; unluckily. [ 1913 Webster ]

2. With a tendency to use the left hand. [ 1913 Webster ]

Many, in their infancy, are sinistrously disposed, and divers continue all their life left-handed. Sir T. Browne. [ 1913 Webster ]

a. [ See Sinister. ] 1. Being on the left side; inclined to the left; sinistral. “Sinistrous gravity.” Sir T. Browne. [ 1913 Webster ]

2. Wrong; absurd; perverse. [ 1913 Webster ]

A knave or fool can do no harm, even by the most sinistrous and absurd choice. Bentley. [ 1913 Webster ]