Even out, late up, a disaster (7)
I believe the answer is:
plateau
'even out' is the definition.
'late up a disaster' is the wordplay.
'disaster' is an anagram indicator.
'late'+'up'+'a'='lateupa'
'lateupa' anagrammed gives 'PLATEAU'.
(Other definitions for plateau that I've seen before include "Table" , "Stop progressing" , "Flat-topped upland" , "one has no inclination" , "level part of range" .)