Moving around old man's nuts (7)
I believe the answer is:
almonds
'nuts' is the definition.
(almond is a kind of nut)
'moving around old man's' is the wordplay.
'moving around' indicates anagramming the letters.
'old'+'mans'='oldmans'
'oldmans' anagrammed gives 'ALMONDS'.
(Other definitions for almonds that I've seen before include "Man sold (anag.)" , "Fruits for marzipan" , "Nuts used to make marzipan" , "Sold man on kind of nuts" .)