Bed starts to creak — replace its base (4)
I believe the answer is:
crib
'bed' is the definition.
(thesaurus)
'starts to creak replace its base' is the wordplay.
'starts to' says to take the initial letters.
The initial letters of 'creak replace its base' is 'CRIB'.
(Other definitions for crib that I've seen before include "Translation cheat; fodder rack" , "Steal - key - child's bed" , "which animals inhabit" , "Cheat - Christmas scene" , "Poor translation" .)