Month men put away ornament (8)
I believe the answer is:
decorate
'ornament' is the definition.
('decorate' can be a synonym of 'ornament')
'month men put away' is the wordplay.
'month' becomes 'dec' (Dec is an example).
'men' becomes 'or' (I've seen this in other clues).
'put away' becomes 'ate' (I've seen this in other clues).
'dec'+'or'+'ate'='DECORATE'
(Other definitions for decorate that I've seen before include "Make more attractive" , "Beautify by additions" , "Add ornamentation to" , "Improve the look of" , "'Adorn, beautify (8)'" .)