Sorceress losing head causes irritation (4)
I believe the answer is:
itch
'irritation' is the definition.
(thesaurus)
'sorceress losing head' is the wordplay.
'sorceress' becomes 'witch' (I've seen this before).
'losing head' means to remove the first letter.
'witch' with its initial letter removed is 'ITCH'.
'causes' is the link.
(Other definitions for itch that I've seen before include "source of irritation" , "are dying" , "Prickling" , "Hunger, longing" , "Feel tingling sensation in skin" .)