Jack shows Silas around island (7)
I believe the answer is:
mariner
'jack' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for mariner that I've seen before include "Sailor" , "Man of the sea" , "See 13" , "'''The Rime of the Ancient ...'' (Coleridge) (7)'" , "Bluejacket" .)