Bones found in sailors' island (5)
I believe the answer is:
tarsi
'bones' is the definition.
(I've seen this before)
'sailors' island' is the wordplay.
'sailors'' becomes 'tars' (tar is a kind of sailor).
'island' becomes 'i'.
'tars'+'i'='TARSI'
'found in' is the link.
(Other definitions for tarsi that I've seen before include "collections of bones?" , "Foot bones" , "parts of leg" , "Ankle bones" , "Bones of the ankles and heels" .)