Read the dictionary definition of subtle. All definitions for this word.
1. working or spreading in a hidden and usually injurious way
1. glaucoma is an insidious disease
2. a subtle poison
2. difficult to detect or grasp by the mind or analyze
1. his whole attitude had undergone a subtle change
2. a subtle difference
3. that elusive thing the soul
3. able to make fine distinctions
1. a subtle mind