Regular case from October and November in journal (8)
I believe the answer is:
ordinary
'regular' is the definition.
(I've seen this before)
'case from october and november in journal' is the wordplay.
'case from' means to remove the middle letters (the case or outside of the word).
'and' means one lot of letters go next to another.
'november' becomes 'n' (phonetic alphabet: alpha, bravo, charlie etc.).
'in' is an insertion indicator.
'journal' becomes 'diary' (synonyms).
'october' with its middle removed is 'or'.
'n' put inside 'diary' is 'dinary'.
'or'+'dinary'='ORDINARY'
(Other definitions for ordinary that I've seen before include "standard" , "pedestrian" , "'Usual, everyday (8)'" , "charge for arms" , "Usual - bishop in his province" .)