Move in or out, as it'll eat away at everything (8)
I believe the answer is:
omnivore
'it'll eat away at everything' is the definition.
I can't judge whether this defines the answer.
'move in or out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'move'+'in'+'or'='moveinor'
'moveinor' anagrammed gives 'OMNIVORE'.
'as' is the link.
Can you help me to learn more?
(Other definitions for omnivore that I've seen before include "unfussy diner" , "Eater of everything" , "Eater of all things" , "Creature eating any type of food" , "It will eat anything, animal or vegetable" .)