adjective sin·is·ter \ˈsi-nə-stər, archaic sə-ˈni-\

Definition of sinister

  1. 1 archaic :  unfavorable, unlucky

  2. 2 archaic :  fraudulent

  3. 3 :  singularly evil or productive of evil

  4. 4a :  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 itb :  of ill omen by reason of being on the left

  5. 5 :  presaging ill fortune or trouble

  6. 6 :  accompanied by or leading to disaster





Examples of sinister in a Sentence

  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

Recent Examples of sinister from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sinister'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

insidious, sinister, or pernicious?

Few would choose to be associated with people or things that are insidious, sinister, or pernicious; all three of these words have decidedly unpleasant meanings, each with its own particular shade of nastiness.

Insidious comes from a Latin word for “ambush” (insidiae), which is fitting, as this word often carries the meanings “deceitful,” “stealthy,” or “harmful in an imperceptible fashion.” The first two meanings may be applied to people or things (“an insidious enemy,” “an insidious plot”), while the last is usually applied to things (“insidious problems,” “insidious sexism”), in particular to the gradual progress of a disease (“an insidious malignancy”).

Sinister comes from a Latin word meaning “on the left side, unlucky, inauspicious.” Although it is commonly used today in the sense “evil” (“a sinister cult leader”; “a sinister plot”), it may also suggest an ominous foreshadowing of some unfavorable turn of events (“a sinister omen”).

Pernicious has largely stayed true to its etymological root, the Latin noun pernicies “ruin, destruction.” Its original meaning in English, “highly injurious or destructive,” usually applies to things (“pernicious apathy,” “pernicious effects”) and medical conditions (“pernicious fever,” pernicious anemia). When applied to people, pernicious means “wicked.”

Is sinister unfair to the left-handed?

Sinister has an etymology that might seem a bit biased against the left-handed portion of the population, as this word, which has had naught but disagreeable meanings for over five hundred years now, comes from a Latin word of the same spelling that means “on the left side.” We find this root in other English words, such as the adjective sinistral (“left-handed”) and the adverb sinistrad (“toward the left side”). To make things even more unfair, the Latin word dexter (“on the right side”) has given rise to English words with largely positive meanings, such as dexterity and ambidextrous.

Origin and Etymology of sinister


Synonym Discussion of sinister


SINISTER Defined for English Language Learners



Definition of sinister for English Language Learners

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

SINISTER Defined for Kids


adjective sin·is·ter \ˈsi-nəs-tər\

Definition of sinister for Students

  1. 1 :  threatening evil, harm, or danger We heard sinister rumors.

  2. 2 :  1evil 1, corrupt We feared he would do something far more sinister.

Seen and Heard

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