D defs.my
Entry 3 senses Webster, 1913

Subtlety

/sŭt'-əl-tē/ · Sub·tle·ty · IPA /ˈsʌt(ə)lti/
01 n. The quality or state of being subtle, or sly; cunning; craftiness; artfulness.
pl. Subtleties ((#))
  1. 1.
    The quality or state of being subtle, or sly; cunning; craftiness; artfulness.
    “The fox which lives by subtlety.” Shak.
  2. 2.
    Nice discernment with delicacy of mental action; nicety of discrimination.
  3. 3.
    Something that is sly, crafty, or delusive.
    “Unlearned in the world's false subtleties.” Shak.