Stop being animated after eating fungus (9)
I believe the answer is:
frustrate
'stop' is the definition.
(I've seen this before)
'animated after eating fungus' is the wordplay.
'animated' indicates anagramming the letters.
'eating' is an insertion indicator.
'fungus' becomes 'rust' (rust fungus is a kind of fungus).
'after' is an anagram of 'frate'.
'frate' placed around 'rust' is 'FRUSTRATE'.
'being' is the link.
(Other definitions for frustrate that I've seen before include "Prevent (plan) from being fulfilled" , "Put a stop to" , "Deprive of hope" , "'Thwart, disappoint (9)'" , "Prevent from progressing" .)