Indian instrument is taken back by sailor (5)
I believe the answer is:
sitar
'indian instrument' is the definition.
(I've seen this before)
'is taken back by sailor' is the wordplay.
'taken back' is a reversal indicator.
'by' says to put letters next to each other.
'sailor' becomes 'tar' (term for a sailor).
'is' in reverse letter order is 'si'.
'si'+'tar'='SITAR'
(Other definitions for sitar that I've seen before include "Lasting from morning to night" , "Indian string instrument" , "Stringed instrument of the subcontinent" , "Plucked instrument" , "It takes pluck" .)