IPA: /sɪˈnɪstrəl/
KK: /sɪˈnɪstrəl/
Relating to or positioned on the left side; often used to describe left-handedness or certain types of shells in zoology.
The sinistral shell of the snail spirals to the left, making it unique among its species.
Sinistral is formed from "sinister" (from Latin, meaning left or on the left side) and the suffix "-al" (meaning pertaining to). The word "sinistral" refers to something that is related to or situated on the left side.
Think of 'sinister' meaning left, and the '-al' indicates it pertains to that side. So, sinistral means something related to the left.