Figure something out about silver, not lead (7)
I believe the answer is:
nonagon
'figure' is the definition.
(shape or figure with 9 sides)
'something out about silver not lead' is the wordplay.
I cannot really understand how this works, but
'about' could be 'on' (as in a book 'on' a certain topic) and 'on' is located in the answer.
'silver' could be 'ag' (Ag is the chemical symbol for silver) and 'ag' is located in the answer.
'not' could be 'non' (I've seen this in other clues) and 'non' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for nonagon that I've seen before include "Nine sided figure" , "Nine-sided polygon" , "Figure with nine, twenty-one Dn" , "Figure with nine sides" , "regular figure" .)