Definitions for subtleˈsʌt l

Random House Webster's College Dictionary

sub•tleˈsʌt l(adj.)-tler, -tlest.

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.
characterized by or requiring mental acuteness, penetration, or discernment.
cunning, wily, or crafty.
insidious in operation:
a subtle poison.
skillful, clever, or ingenious.

Origin of subtle:

1250–1300; ME sotil < OF < L subtīlissubtile

sub′tly(adv.)

Princeton's WordNet

elusive, subtle(adj)
difficult to detect or grasp by the mind or analyze
"his whole attitude had undergone a subtle change"; "a subtle difference"; "that elusive thing the soul"
subtle(adj)
able to make fine distinctions
"a subtle mind"
insidious, pernicious, subtle(adj)
working or spreading in a hidden and usually injurious way
"glaucoma is an insidious disease"; "a subtle poison"

Kernerman English Learner's Dictionary

subtle(adjective)ˈsʌt l
affecting sth in a way that is not obvious
subtle changes in her mood; The transition was subtle.
subtleˈsʌt l
pleasant and not too strong
a subtle flavor of ginger
subtleˈsʌt l
creative and intelligent in a way that is not too obvious
a subtle argument; His acting was subtle but powerful.; He tried subtly to convince his son.; subtly shaded black-and-white photographs

Wiktionary

subtle(Adjective)
Hard to grasp; not obvious or easily understood; barely noticeable.
The difference is subtle, but you can hear it if you listen carefully.
subtle(Adjective)
Cleverly contrived.
subtle(Adjective)
Cunning, skillful.
subtle(Adjective)
insidious
subtle(Adjective)
Tenuous; rarefied; of low density or thin consistency.

Origin: From sotil, subtil, from soutil, later subtil, subtil, from subtilis; probably, originally, “woven fine”, and from sub + tela, from texere.

Webster Dictionary

Subtle(u)
sly in design; artful; cunning; insinuating; subtile; -- applied to persons; as, a subtle foe
Subtle(u)
cunningly devised; crafty; treacherous; as, a subtle stratagem
Subtle(u)
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
Subtle(u)
smooth and deceptive