thin, tenuous, or rarefied, as a fluid or an odor.

fine or delicate in meaning or intent; difficult to perceive or understand

subtle irony.

delicate or faint and mysterious

a subtle smile.

requiring mental acuteness, penetration, or discernment

a subtle philosophy.

characterized by mental acuteness or penetration

a subtle understanding.

cunning, wily, or crafty

a subtle liar.

insidious in operation

subtle poison.

skillful, clever, or ingenious

a subtle painter.

adjective

hard , harsh , noisy , unsubtle , forthright , honest , open

adjective

attenuate , attenuated , deep , discriminating , ethereal , exquisite , faint , fine , finespun , hairline , hairsplitting , illusive , implied , inconspicuous , indirect , indistinct , inferred , ingenious , insinuated , mental , penetrating , profound , refined , slight , sophisticated , suggestive , tenuous , thin , understated , analytic , analytical , artful , astute , complex , crafty , designing , detailed , devious , dexterous , exacting , foxy , guileful , insidious , intriguing , keen , perceptive , precise , ratiocinative , scheming , shrewd , skillful , sly , wily , nice , delicate , abstruse , acute , beguiling , cagy , clever , cunning , deceptive , deft , elusive , expert , imperceptible , indefinable , intangible , intricate , logical , quibbling , quiet , scholastic , sharp , slick , sophistical , vague