Silly figure after a number minus ten (7)
I believe the answer is:
asinine
'silly' is the definition.
(I've seen this before)
'figure after a number minus ten' is the wordplay.
'figure' becomes 'nine' (a number of figure).
'after' means one lot of letters go next to another.
'a number minus ten' becomes 'asi' (I can't explain this - if you can you should believe this answer much more).
'nine' after 'asi' is 'ASININE'.
Can you help me to learn more?
(Other definitions for asinine that I've seen before include "Foolish, silly" , "Is inane to be foolish" , "Foolish like donkey" , "'Mindless, vacuous (7)'" , "In the nature of supposedly stupid animal" .)