It has its sandy side (3)
I believe the answer is:
sea
'sandy side' is the definition.
The definition and answer can be both natural objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'it has its' is the wordplay.
'it' becomes 'sa' (old-fashioned abbreviation for sex appeal).
'has' indicates putting letters inside.
'its' becomes 'e' (I am not sure about this - if you are sure you should believe this answer much more).
'sa' enclosing 'e' is 'SEA'.
Can you help me to learn more?
(Other definitions for sea that I've seen before include "Large body of salt water" , "Body of saltwater" , "eg Galilee" , "eg Dead, Red" , "Cod's home?" .)