Synonyms for Sinister

Synonyms starting with letter U

• unfavorable

  nasty
• unpropitious

  ill-omened, nasty
• unfortunate

  ominous, nasty
• unlucky

  nasty
• unfavourable

  ominous
• unkind

  ominous
• unpromising
• untoward
• unfriendly
• unpleasant
• uncanny
• 

  ugly
• unearthly
• underhand
• unscrupulous
• underhanded
• ungodly

  characteristic
• unholy
• upsetting
• unprincipled
• unsettling
• unhealthy
• unwholesome
• unethical
• unspeakable
• unnatural
• unnerving
• unfaithful

  dishonest
• unfair
• untrustworthy
• unctuous
• unrelenting
• unyielding
• uncertain
• unfitting
• unwarranted
• unjust
• unreasonable
• unseemly
• unjustified