Potentially integral figure (8)
I believe the answer is:
triangle
'figure' is the definition.
(triangle is a kind of figure)
'potentially integral' is the wordplay.
'potentially' indicates an anagram (letters have the potential to spell a new word).
'integral' is an anagram of 'TRIANGLE'.
(Other definitions for triangle that I've seen before include "Three-sided shape" , "Large tin (anag.)" , "diamond cut in half?" , "It could be eternal" , "Integral part of common geometric figure" .)