Applaud a demand on the insurer, say (7)
I believe the answer is:
acclaim
'applaud' is the definition.
(synonyms)
'a demand on the insurer say' is the wordplay.
'a demand' becomes 'claim' (claim is a kind of demand).
'on' says to put letters next to each other.
'the insurer say' becomes 'ac' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'claim' put after 'ac' is 'ACCLAIM'.
Can you help me to learn more?
(Other definitions for acclaim that I've seen before include "Laud" , "Welcome with shouts of applause" , "Credit" , "Enthusiastic approval" , "Welcome enthusiastically" .)