Stick with a Scottish island (6)
I believe the answer is:
staffa
'scottish island' is the definition.
(I've seen this before)
'stick with a' is the wordplay.
'stick' becomes 'staff' (staff is a kind of stick).
'with' says to put letters next to each other.
'staff'+'a'='STAFFA'
(Other definitions for staffa that I've seen before include "Fingal's Cave location" , "Island west of Mull" , "Hebridean island: site of Fingal's Cave" , "Fingal's cave isle" , "Inch" .)