Delete part of chapter, as expected (5)
I believe the answer is:
erase
'delete' is the definition.
(I know that delete can be written as erase)
'part of chapter as expected' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'ERASE' is hidden in the letters of 'chapter as expected'.
(Other definitions for erase that I've seen before include "Rub out, cancel" , "Remove all traces of" , "Blot out" , "score" , "Remove permanently" .)