Compensation as mother gets older (7)
I believe the answer is:
damages
'compensation' is the definition.
(damages is a kind of compensation)
'mother gets older' is the wordplay.
'mother' becomes 'dam' (female parent of an animal).
'gets older' becomes 'ages' ('age' can be a synonym of 'get older').
'dam'+'ages'='DAMAGES'
'as' acts as a link.
(Other definitions for damages that I've seen before include "Money paid in compensation for loss or injury" , "Moneys paid as compensation for an injury" , "Harms" , "Money awarded as compensation" , "Hurts" .)