Appeal during boring game creates irritation (9)
I believe the answer is:
itchiness
'irritation' is the definition.
(irritation somewhere on the body)
'appeal during boring game' is the wordplay.
'appeal' becomes 'it' ('it' can mean something attractive or appealing).
'during' becomes 'in' (e.g. during February means in February).
'boring' is an insertion indicator (some letters must 'bore' a hole into other letters).
'game' becomes 'chess' (board game).
'in' going within 'chess' is 'chiness'.
'it'+'chiness'='ITCHINESS'
'creates' acts as a link.
(Other definitions for itchiness that I've seen before include "Skin irritation" , "It produces the desire to scratch" , "Feeling of irritation" , "irritating" , "tingling" .)