Previous erratum to be corrected in returned English page (9)
I believe the answer is:
premature
'previous' is the definition.
(thesaurus)
'erratum to be corrected in returned english page' is the wordplay.
'to be corrected' indicates an anagram.
'in' means one lot of letters goes inside another.
'returned' is a reversal indicator.
'english' becomes 'e' (abbreviation).
'page' becomes 'p'.
'e'+'p'='ep'
'ep' written backwards gives 'pe'.
'erratum' anagrammed gives 'rematur'.
'rematur' inserted inside 'pe' is 'PREMATURE'.
(Other definitions for premature that I've seen before include "Occurring before the expected time" , "Early" , "Too soon or too hasty" , "Over-hasty" , "Untimely" .)