Study a number of points (3)
I believe the answer is:
den
'study' is the definition.
(term for a study or office)
'a number of points' is the wordplay.
'a number' becomes 'D' (D is an example).
'of points' becomes 'en' (I can't justify this - if you can you should believe this answer much more).
'd'+'en'='DEN'
Can you help me to learn more?
(Other definitions for den that I've seen before include "Wild animal's lair" , "Miserable place" , "Animals' shelter" , "Hidden lair of an animal" , "Home of the beast" .)