| Answer | Crossword Clue |
|---|---|
| OUTERATMOSPHERE | Layer of thinnest air |
| RAREST | Thinnest, as air. |
| cushions | The layer of air supporting a hovercraft or similar vehicle |
| pleuston | organisms living in the thin surface layer existing at the air-water interface of a body of water |
| plastrons | (in an aquatic insect) A patch of cuticle covered with hairs that retain a thin layer of air, acting like a gill for breathing under water |
