sinister

[sin-uh-ster]

adjective

1. threatening or portending evil, harm, or trouble; ominous.

   a sinister remark.

   Synonyms: portentous, inauspicious
   Antonyms: benign

2. bad, evil, base, or wicked; fell.

   his sinister purposes.

3. unfortunate; disastrous; unfavorable.

   a sinister accident.

   Synonyms: unlucky
   Antonyms: favorable

4. of or on the left side; left.

5. Heraldry.,  noting the side of an escutcheon or achievement of arms that is to the left of the bearer (dexter ).

sinister

/ ˈsɪnɪstə /

adjective

1. threatening or suggesting evil or harm; ominous

   a sinister glance

2. evil or treacherous, esp in a mysterious way

3. (usually postpositive) heraldry of, on, or starting from the left side from the bearer's point of view and therefore on the spectator's right

4. archaic,  located on the left side

5. archaic,  (of signs, omens, etc) unfavourable

Other Word Forms

• sinisterly adverb
• sinisterness noun
• unsinister adjective
• unsinisterly adverb
• unsinisterness noun

Word History and Origins

Origin of sinister¹

First recorded in 1375–1425; late Middle English, from Latin: “on the left hand or side,” hence, “unfavorable, injurious”

Word History and Origins

Origin of sinister¹

C15: from Latin sinister on the left-hand side, considered by Roman augurs to be the unlucky one

Example Sentences

Instead, “Him” wonders what kind of spiritual practice it is: hero worship or a sinister cult?

From Los Angeles Times

But when the encounter gets more tense, Mancuso unveils his lethal side, his smile dissolving into a sinister glare as he knocks a cup of hot coffee into Jake’s lap.

From Los Angeles Times

That series revolved around an aspiring comedian’s increasingly sinister encounters with an eccentric woman.

From Los Angeles Times

The fourth album by Dublin's Fontaines DC sees the quintet take their scratchy, sinister sound and run it through a Technicolor filter.

From BBC

This often attracts attention among online conspiracy theorists, who falsely claim that condensation trails in the sky – water vapour created from aircraft jet engines – is evidence of sinister large-scale geoengineering today.

From BBC

Related Words

• dire 
• evil 
• malevolent 
• mischievous 
• ominous 
• perverse 
• threatening