subtle

(adjective)

adjective

1. difficult to detect or grasp by the mind or analyze

- his whole attitude had undergone a subtle change

- a subtle difference

Similar word(s): impalpable, elusive

2. able to make fine distinctions

- a subtle mind

Similar word(s): perceptive

3. working or spreading in a hidden and usually injurious way

- a subtle poison

Similar word(s): harmful, insidious, pernicious

Sentences with subtle as an adjective:

- The difference is subtle, but you can hear it if you listen carefully.