SUBTILTY
Noun
subtilty (countable and uncountable, plural subtilties)
Archaic spelling of subtlety.
Source: Wiktionary
Sub"til*ty, n. Etym: [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.
Note: In senses 2, 3, and 4 the word is more commonly written
subtlety.
Source: Webster’s Unabridged Dictionary 1913 Edition