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.
SUBTLE Sub"tle, a. [Compar. Subtler; superl. Subtlest.] Etym: [OE. sotil, subtil, OF. soutil, later subtil, F. subtil, L. subtilis; probably, originally, woven fine, and fr. sub under + tela a web, fr. texere to weave. See Text, and cf. Subtile.]
1. Sly in design; artful; cunning; insinuating; subtile; — applied to persons; as, a subtle foe. "A subtle traitor." Shak.
2. Cunningly devised; crafty; treacherous; as, a subtle stratagem.
3. Characterized by refinement and niceness in drawing distinctions; nicely discriminating; — said of persons; as, a subtle logician; refined; tenuous; sinuous; insinuating; hence, penetrative or pervasive; — said of the mind; its faculties, or its operations; as, a subtle intellect; a subtle imagination; a subtle process of thought; also, difficult of apprehension; elusive. Things remote from use, obscure and subtle. Milton.
4. Smooth and deceptive. [Obs.] Like to a bowl upon a subtle ground [bowling ground]. Shak.
Syn. — Artful; crafty; cunning; shrewd; sly; wily. Subtle is the most comprehensive of these epithets and implies the finest intellectual quality. See Shrewd, and Cunning.