The definition of sinister is a person or thing that threatens harm or misfortune.
(adjective)See sinister in Webster's New World College Dictionary
adjective
Origin: ME sinistre < L sinister, left-hand, or unlucky (side), orig. lucky (side) < IE base *sene-, to prepare, achieve > Sans sánīyān, more favorable: early Roman augurs faced south, with the east (lucky side) to the left, but the Greeks (followed by later Romans) faced north
Related Forms:
See sinister in American Heritage Dictionary 4
adjective
Origin:
Origin: Middle English sinistre, unfavorable
Origin: , from Old French
Origin: , from Latin sinister, on the left, unlucky
.Related Forms:
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