Moderate team peter out (9)
I believe the answer is:
temperate
'moderate' is the definition.
('temperate' can be a synonym of 'moderate')
'team peter out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'team'+'peter'='teampeter'
'teampeter' anagrammed gives 'TEMPERATE'.
(Other definitions for temperate that I've seen before include "sober" , "Restrained" , "It is reasonable" , "Showing self-restraint" , "Abstemious" .)