The quality or state of being subtle, especially in a way that is not immediately obvious or noticeable. The subtlety of her argument was lost on those who were not paying close attention.
A fine or delicate detail or distinction that is not immediately obvious. The artist's work is full of subtleties that reveal themselves upon closer inspection.
(historical) A highly decorative dish or confection served between courses at medieval banquets. At the royal feast, the cooks presented a marzipan subtlety shaped like a castle.
(archaic) Craftiness or skill in achieving one's aims by indirect or delicate means; cunning. He defeated his political rivals by subtlety rather than by force.