Call on grandma, mum and uncle last of all (4)
I believe the answer is:
name
'call' is the definition.
(as in calling or naming someone something)
'grandma mum and uncle last of all' is the wordplay.
'grandma mum' becomes 'nam' (I can't justify this - if you can you should give a lot more credence to this answer).
'and' is a charade indicator (letters next to each other).
'last of all' indicates one should take the final letters.
The last letter of 'uncle' is 'e'.
'nam'+'e'='NAME'
'on' is the link.
Can you help me to learn more?
(Other definitions for name that I've seen before include "celebrity" , "Amen (anag)" , "Title; famous person" , "Good reputation; specify; christen" , "Mean sort of appellation" .)