Make intelligible point after attack (7)
I believe the answer is:
decrypt
'make intelligible' is the definition.
'point after attack' is the wordplay.
'point' becomes 'pt'.
'after' is a charade indicator (letters next to each other).
'attack' becomes 'decry'.
'pt' after 'decry' is 'DECRYPT'.
(Other definitions for decrypt that I've seen before include "Crack" , "Translate from code" , "Use key" , "Break code" , "Make sense of" .)