| Adj. | 1. | subtle - be difficult to detect or grasp by the mind; "his whole attitude had undergone a subtle change"; "a subtle difference"; "that elusive thing the soul"impalpable - imperceptible to the senses or the mind; "an impalpable cloud"; "impalpable shadows"; "impalpable distinctions"; "as impalpable as a dream" | |
| 2. | subtle - faint and difficult to analyze; "subtle aromas"delicate - exquisitely fine and subtle and pleasing; susceptible to injury; "a delicate violin passage"; "delicate china"; "a delicate flavor"; "the delicate wing of a butterfly" | |
| 3. | subtle - able to make fine distinctions; "a subtle mind"perceptive - having the ability to perceive or understand; keen in discernment; "a perceptive eye"; "a perceptive observation" | |
| 4. | subtle - working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison"harmful - causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking" | |