early 15c., sinistralle, "unlucky, adverse" (a sense now obsolete), from Old French senestral, sinistral or Medieval Latin *sinistralis, from Latin sinister "left, on the left side" (see sinister). The meaning "on, of, or pertaining to the left side" is from 1803. Of persons, "left-handed," by 1904. Related: Sinistrally; sinistrality.
updated on November 06, 2022