Gold? Blow in a month? (6)
I believe the answer is:
august
'a month?' is the definition.
(I know that August is a type of Gregorian calendar month)
'gold? blow' is the wordplay.
'gold?' becomes 'Au' (Au is the chemical symbol for gold).
'blow' becomes 'gust' (as in a gust of wind).
'au'+'gust'='AUGUST'
'in' acts as a link.
(Other definitions for august that I've seen before include "part of the year" , "Distinguished" , "A grand month?" , "Pale-faced fool" , "Inspiring reverence" .)