Also covering a case in the West Indies (6)
I believe the answer is:
tobago
'in the west indies' is the definition.
('Tobago' is part of 'west indies')
'also covering a case' is the wordplay.
'also' becomes 'too' (synonyms).
'covering' is an insertion indicator.
'a case' becomes 'bag' (bag is a kind of case).
'too' placed around 'bag' is 'TOBAGO'.
(Other definitions for tobago that I've seen before include "Trinidad and - (WI)" , "Trinidad companion island" , "West Indian island" , "Trinidad's smaller partner island" , "Caribbean island" .)