Parts of body, on the bottom? (5)
I believe the answer is:
soles
'parts' is the definition.
(sol is a kind of part)
'of body on the bottom?' is the wordplay.
'of body' becomes 's' (I can't justify this - if you can you should give a lot more credence to this answer).
'on' means one lot of letters go next to another.
'the bottom?' becomes 'sole' (sole is a kind of bottom).
's' put after 'sole' is 'SOLES'.
Can you help me to learn more?
(Other definitions for soles that I've seen before include "Undersides of feet" , "They're always under one's feet!" , "Shoe bottoms" , "Fish; bottoms of feet" , "Undersurfaces of feet" .)