Peers corrected worker initially over language (9)
I believe the answer is:
esperanto
'language' is the definition.
(Esperanto is an example)
'peers corrected worker initially over' is the wordplay.
'corrected' indicates an anagram.
'worker' becomes 'ant' (worker is a type of ant).
'initially' suggests taking the first letters.
The first letter of 'over' is 'o'.
'peers' anagrammed gives 'esper'.
'esper'+'ant'+'o'='ESPERANTO'
(Other definitions for esperanto that I've seen before include "words, set up artificially?" , "Ape tenors (anag.)" , "composite language" , "Personate in artificial language" , "Personate (anag.)" .)