Instrument from India encased in lead (5)
I believe the answer is:
sitar
'instrument' is the definition.
(sitar is a kind of instrument)
'india encased in lead' is the wordplay.
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
'encased in' is an insertion indicator.
'lead' becomes 'star' (synonyms).
'i' placed inside 'star' is 'SITAR'.
'from' acts as a link.
(Other definitions for sitar that I've seen before include "Astir with Indian long-necked lute" , "Indian stringed instrument" , "Hindu stringed instrument" , "Hindu string instrument" , "Large Indian lute" .)