Most of panel on a Scottish island (4)
I believe the answer is:
jura
'scottish island' is the definition.
'Jura' can be an answer for 'island' (I've seen this before). I also know that 'scottish' relates to this answer.
'most of panel on a' is the wordplay.
'most of' means to remove the last letter.
'panel' becomes 'jury' ('jury' can be a synonym of 'panel').
'on' means one lot of letters go next to another.
'jury' with its last letter taken off is 'jur'.
'jur'+'a'='JURA'
(Other definitions for jura that I've seen before include "Inner Hebridean isle" , "island > range" , "Scottish island -- mountains on the French-Swiss border" , "Inner Hebrides island" , "Hebridean island" .)