adjective subtler , subtlest
- thin; rare; tenuous; not dense or heavy: a subtle gas
- capable of making or noticing fine distinctions in meaning, etc.: a subtle thinker
- marked by or requiring mental keenness: subtle reasoning
- delicately skillful or clever; deft or ingenious: a subtle filigree
- not open or direct; crafty; sly
- delicately suggestive; not grossly obvious: a subtle hint
- working insidiously; not easily detected: a subtle poison