Skinhead has issue, I note (8)
I believe the answer is:
semitone
'note' is the definition.
(thesaurus)
'skinhead has issue i' is the wordplay.
'skinhead' becomes 's' (head letter of 'skin').
'has' says to put letters next to each other.
'issue' becomes 'emit' (both can mean to give out or radiate).
'i' becomes 'one' (Roman numeral for one).
's'+'emit'+'one'='SEMITONE'
(Other definitions for semitone that I've seen before include "Small interval between notes" , "100 cents" , "One twelfth of an octave" , "Interval between adjacent keys, on a piano say" , "Small musical interval" .)