American Heritage Dictionary
(6)
Century Dictionary
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GNU Webster's 1913
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WordNet
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Elsewhere on the web
The trend of progress is constantly discarding the more ponderous and clumsy for the subtle, the swift, and the more ethereal form of mechanism.— The Life Radiant
Neither referred to Sir Donald's whim in remaining behind Oswald had spent a half-hour alone with this interesting girl without reference to the mystery which had eluded his subtle, absorbing inquiry for the past three weeks Upon being joined by Sir Donald, the party rode on for some distance along the bank of a lake, until coming to a graveled road and following its meandering course, they returned to the Northfield mansion Next day was the Sabbath.— Oswald Langdon or, Pierre and Paul Lanier. A Romance of 1894-1898
It was not that when she tried to be what she called subtle (for wasn't Limbert subtle, and wasn't I?)— Embarrassments
It was splendid work--subtle, excruciatingly funny, and possessed a dash and go that would sweep all carping and criticism before it Food was still scarce, and there was no fuel even to cook things; but as there was nothing to cook, it really made no difference.— Little Journeys to the Homes of the Great - Volume 14 Little Journeys to the Homes of Great Musicians
He might try to be subtle, he might even be subtle--for him.— The Call of the Blood

American Heritage Dictionary (1)
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