Subtilty

Sub"til*ty (?), n. [Contr. fr. subtility.] 1. The quality or state of being subtile; thinness; fineness; as, the subtility of air or light.

2. Refinement; extreme acuteness; subtlety.

Intelligible discourses are spoiled by too much subtility in nice divisions.
Locke.

3. Cunning; skill; craft. [Obs.]

To learn a lewd man this subtility.
Chaucer.

4. Slyness in design; artifice; guile; a cunning design or artifice; a trick; subtlety.

O full of all subtility and all mischief.
Acts xiii. 10.

☞ In senses 2, 3, and 4 the word is more commonly written subtlety.