Definition of sinistrously in English:

sinistrously

Pronunciation /ˈsɪnɪstrəsli/

adverb

rare
  • 1In a manner which provokes dread or foreboding; ominously, threateningly.

  • 2With a tendency to use the left hand in preference to the right; with the left hand.

Origin

Late Middle English (in an earlier sense). From sinistrous + -ly.