In a way that is delicate, understated, or difficult to detect. With nuance and refinement rather than obviousness.
From Latin 'subtilis' meaning 'finely woven' or 'thin', from 'sub-' (under) and 'tela' (web). The evolution from physical fineness to intellectual or artistic refinement reflects how we understand delicacy in both material and abstract terms.
The 'b' in 'subtly' is often silent in pronunciation, making it a spelling challenge - this reflects the word's own meaning of being understated and easy to miss! Great actors are praised for subtle performances because they convey complex emotions without obvious theatrical gestures, much like how the word itself hides one of its letters.
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