Speaks harshly of making a pass at a redhead (5)
I believe the answer is:
rasps
'speaks harshly' is the definition.
(I've seen this in another clue)
'making a pass at a redhead' is the wordplay.
'making' is an anagram indicator.
'at' means one lot of letters go next to another (I've seen this in other clues).
'a redhead' becomes 'r' (head letter of 'red').
'pass' is an anagram of 'asps'.
'asps' after 'r' is 'RASPS'.
'of' is the link.
(Other definitions for rasps that I've seen before include "Coarse files" , "Scrapes" , "fruit briefly" , "Jars" , "Grates harshly" .)