Sŭb'til-ty, n.

n. [Contracted from subtility, q. v.] 1. The state or quality of being subtile; thinness; fineness; exility; as, the subtility of air or light; the subtility of sounds. 2. Refinement; extreme acuteness. Intelligible discourses are spoiled by too much subtility in nice divisions. Locke. 3. Slyness in design; cunning; artifice. ☞ In the last two senses, the word is more commonly written subtlety. 4. A cunning device, symbol, or emblem. [Obs.]