(1):

(n.) Cunning; skill; craft.

(2):

(n.) Refinement; extreme acuteness; subtlety.

(3):

(n.) The quality or state of being subtile; thinness; fineness; as, the subtility of air or light.

(4):

(n.) Slyness in design; artifice; guile; a cunning design or artifice; a trick; subtlety.