Employees on a Scottish island (6)
I believe the answer is:
staffa
'scottish island' is the definition.
(I've seen this before)
'employees on a' is the wordplay.
'employees' becomes 'staff' (I've seen this in another clue).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'staff'+'a'='STAFFA'
(Other definitions for staffa that I've seen before include "Scottish island" , "Island west of Mull" , "small uninhabited island" , "Hebridean island: site of Fingal's Cave" , "Fingal's Cave location" .)