1. of or on the left - a sinistral gastropod shell with the apex upward has its opening on the left when facing the observer - a sinistral flatfish lies with the left eye uppermost • Ant: dextral • Similar to: sinister, sinistrorse, sinistrorsal • See Also: counterclockwise, anticlockwise, contraclockwise, left-handed 2. preferring to use left foot or hand or eye - sinistral individuals exhibit dominance of the left hand and eye • Similar to: left-handed • Derivationally related forms: sinistrality