adjective sin·is·ter \ˈsi-nəs-tər, archaic sə-ˈnis-\

: having an evil appearance : looking likely to cause something bad, harmful, or dangerous to happen

Full Definition of SINISTER

archaic :  unfavorable, unlucky
archaic :  fraudulent
:  singularly evil or productive of evil
a :  of, relating to, or situated to the left or on the left side of something; especially :  being or relating to the side of a heraldic shield at the left of the person bearing it
b :  of ill omen by reason of being on the left
:  presaging ill fortune or trouble
:  accompanied by or leading to disaster
sin·is·ter·ly adverb
sin·is·ter·ness noun

Examples of SINISTER

  1. There was something sinister about him.
  2. <the movie relies too much on sinister background music to create the suspense that the plot sorely lacks>

Origin of SINISTER

Middle English sinistre, from Anglo-French senestre on the left, from Latin sinistr-, sinister on the left side, unlucky, inauspicious
First Known Use: 15th century

Synonym Discussion of SINISTER

sinister, baleful, malign mean seriously threatening evil or disaster. sinister suggests a general or vague feeling of fear or apprehension on the part of the observer <a sinister aura haunts the place>. baleful imputes perniciousness or destructiveness to something whether working openly or covertly <exerting a corrupt and baleful influence>. malign applies to what is inherently evil or harmful <the malign effects of racism>.
SINISTERLY Defined for Kids


adjective sin·is·ter \ˈsi-nəs-tər\

Definition of SINISTER for Kids

:  threatening evil, harm, or danger <We heard sinister rumors.>
:  1evil 1, corrupt <We feared he would do something far more sinister.>


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