'Subtly' definitions:

Definition of 'subtly'

From: WordNet
adverb
In a subtle manner; "late nineteenth-century French opera at its most beautiful, subtly romantic with a twilight melancholy"

Definition of 'Subtly'

From: GCIDE
  • Subtly \Sub"tly\, adv. In a subtle manner; slyly; artfully; cunningly. [1913 Webster]
  • Thou seest how subtly to detain thee I devise. --Milton. [1913 Webster]
  • 2. Nicely; delicately. [1913 Webster]
  • In the nice bee what sense so subtly true. --Pope. [1913 Webster]
  • Subtly communicating itself to my sensibilities, but evading the analysis of my mind. --Hawthorne. [1913 Webster]
  • 3. Deceitfully; delusively. [Obs.] --Shak. [1913 Webster]