Mr Lynam makes many points (3)
I believe the answer is:
des
'mr' is the definition.
'lynam makes many points' is the wordplay.
I cannot really see how this works, but
'many' could be 'd' (Roman numeral for 500) and 'd' is found within the answer.
'points' could be 'es' (two compass points) and 'es' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for des that I've seen before include "and 9 Across: Former 'Countdown' host" , "- O'Connor, Br. singer" .)