Sailor held back by soldiers gets free (6)
I believe the answer is:
gratis
'free' is the definition.
(I know that free can be written as gratis)
'sailor held back by soldiers' is the wordplay.
'sailor' becomes 'gris' (I can't justify this - if you can you should give a lot more credence to this answer).
'held' indicates putting letters inside.
'back by' shows that the letters should be reversed in order.
'soldiers' becomes 'TA' (abbreviation for Territorial Army).
'ta' back-to-front is 'at'.
'gris' enclosing 'at' is 'GRATIS'.
'gets' is the link.
Can you help me to learn more?
(Other definitions for gratis that I've seen before include "not charged" , "Free of charge" , "Without payment" , "On the house" , "Free, at no cost" .)