subtlea.[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.(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.()Like to a bowl upon a subtle ground [bowling ground]. (Shak.)()()