Dressing might start in October (4)
I believe the answer is:
mayo
'dressing' is the definition.
(mayo is a condiment or dressing)
'might start in october' is the wordplay.
'might' becomes 'may' (I've seen this before).
'start in' says to take the initial letters.
The initial letter of 'october' is 'o'.
'may'+'o'='MAYO'
(Other definitions for mayo that I've seen before include "Irish county -- salad cream" , "Irish county; dressing" , "radio presenter" , "Eg, Braeburn or Cox" , "County of Western Eire" .)