Boarding house resident is no youngster (9)

I believe the answer is:
pensioner
'no youngster' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'boarding house resident' is the wordplay.
'boarding house' becomes 'pension' (I've seen this before).
'resident' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
'pension'+'er'='PENSIONER'
'is' is the link.
Can you help me to learn more?
(Other definitions for pensioner that I've seen before include "Former worker" , "One past retirement" , "senior citizen" , "retiree" , "beneficiary of fund" .)
