The fewer you have the less you want (5)
I believe the answer is:
needs
'the fewer you have the less you want' is the definition.
I can't tell whether this defines the answer.
'the fewer you have the less you' is the wordplay.
'the fewer you' becomes 'neds' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'have' means one lot of letters goes inside another.
'less' indicates named letters should be taken away.
'you' becomes 'thee' (I've seen this before).
'thee' with 'the' taken away is 'e'.
'neds' going around 'e' is 'NEEDS'.
Can you help me to learn more?
(Other definitions for needs that I've seen before include "Necessitates" , "Things that are wanted" , "necessity once" , "Requires or lacks" , "What we require" .)