It eats almost everything (6,4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
nitric acid
'it eats almost everything' is the definition.
The definition suggests a singular noun which matches the answer.
This is all the clue.
Can you help me to learn more?
(Other definitions for nitric acid that I've seen before include "Corrosive liquid" , "component of explosive" , "dangerous stuff?" .)