Saint gets drink that's not fresh (5)
I believe the answer is:
stale
'that's not fresh' is the definition.
(stale is the opposite of fresh)
'saint gets drink' is the wordplay.
'saint' becomes 'st' (abbreviation).
'gets' means one lot of letters go next to another.
'drink' becomes 'ale' (type of beer).
'st'+'ale'='STALE'
(Other definitions for stale that I've seen before include "No longer take" , "Unfresh" , "No longer fresh" , "Lacking freshness" , "past the sell-by date" .)