What does "sinister" mean?

Sinister: Unlucky; inauspicious; disastrous; injurious; evil; -- the left being usually regarded as the unlucky side; as, sinister influences. All the several ills that visit earth, Brought forth by night, with a sinister birth. B. Jonson.

Additional senses

  1. 2.Wrong, as springing from indirection or obliquity; perverse; dishonest; corrupt; as, sinister aims. Nimble and sinister tricks and shifts. Bacon. He scorns to undermine another's interest by any sinister or inferior arts. South. He read in their looks . . . sinister intentions directed particularly toward himself. Sir W. Scott.
  2. 3.Indicative of lurking evil or harm; boding covert danger; as, a sinister countenance. Bar sinister. (Her.) See under Bar, n. -- Sinister aspect (Astrol.), an appearance of two planets happening according to the succession of the signs, as Saturn in Aries, and Mars in the same degree of Gemini. -- Sinister base, Sinister chief. See under Escutcheon.

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