Main Entry: sin·is·ter

Pronunciation: \ˈsi-nəs-tər, archaic sə-ˈnis-\

Function: adjective

Etymology: Middle English sinistre, from Anglo-French senestre on the left, from Latin sinistr-, sinister on the left side, unlucky, inauspicious

Date: 15th century

1 archaic : unfavorable, unlucky
2 archaic : fraudulent
3 : singularly evil or productive of evil
4 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
5 : presaging ill fortune or trouble
6 : accompanied by or leading to disaster

— sin·is·ter·ly adverb

— sin·is·ter·ness noun

synonyms 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>.