subtle (ˈsʌt ə l)
— adj
1. not immediately obvious or comprehensible
2. difficult to detect or analyse, often through being delicate or highly refined: a subtle scent
3. showing or making or capable of showing or making fine distinctions of meaning
4. marked by or requiring mental acuteness or ingenuity; discriminating
5. delicate or faint: a subtle shade
6. cunning or wily: a subtle rogue
7. operating or executed in secret: a subtle intrigue