Subtile

1.

Thin; not dense or gross; rare; as, subtile air; subtile vapor; a subtile medium.

2.

Delicately constituted or constructed; nice; fine; delicate; tenuous; finely woven.

3.

Acute; piercing; searching.

4.

Characterized by nicety of discrimination; discerning; delicate; refined; subtle.

5.

Sly; artful; cunning; crafty; subtle; as, a subtile person; a subtile adversary; a subtile scheme.