Savings teens misused going on vacation (4,3)
I believe the answer is:
nest egg
'savings' is the definition.
(nest egg can mean someone's savings)
'teens misused going on vacation' is the wordplay.
'misused' indicates an anagram.
'going on' becomes 'going' (going is a kind of going on).
'vacation' suggests removing the centre (middle letters vacate the word).
'going' with its middle taken out is 'gg'.
'teens' with letters rearranged gives 'neste'.
'neste'+'gg'='NEST-EGG'
(Other definitions for nest egg that I've seen before include "a little money?" , "Is it to encourage laying" , "Fund for a rainy day" , "Reserve funds" , "Savings for the future" .)