Conspiratorial (adjective)

  1. Of or relating to a secret plan or agreement to do something illegal or harmful.
  2. Of or relating to a secret plan or scheme to achieve a particular goal.
  3. Relating to or suggestive of conspiracy.

Origin:

Late 19th century: from conspirator + -ial.

Examples:

  1. He had a conspiratorial look in his eye, which made me suspicious.
  2. The police discovered a conspiratorial note that provided evidence of the plot.
  3. The conspiratorial whispers among the group raised suspicions among the authorities.
  4. She had a conspiratorial smile as she shared her secret plan with me.
  5. The conspiratorial tone in his voice made me think that he was involved in some illegal scheme.
Some random words: clearance, strategist, betterment