Mother comes with a loaf of bread (6)
I believe the answer is:
damper
'loaf of bread' is the definition.
'mother comes with a' is the wordplay.
'mother' becomes 'dam' (female parent of an animal**).
'comes with' says to put letters next to each other.
'a' becomes 'per'.
'dam'+'per'='DAMPER'
(Other definitions for damper that I've seen before include "Piano piece" , "bush bread" , "Piano string silencer" , "Vibration reducer" , "more soppy" .)