In time we replace pitcher (4)
I believe the answer is:
ewer
'pitcher' is the definition.
(synonyms)
'in time we replace' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EWER' is hidden within 'time we replace'.
(Other definitions for ewer that I've seen before include "Large water-jug" , "A wide-lipped jug" , "Large pitcher" , "Jar for water" , "Vessel for pouring" .)