Sailor cheers end of tour (3)
I believe the answer is:
tar
'sailor' is the definition.
(slang term for a sailor)
'cheers end of tour' is the wordplay.
'cheers' becomes 'ta' (both can mean thank you).
'end of' indicates one should take the final letters.
The last letter of 'tour' is 'r'.
'ta'+'r'='TAR'
(Other definitions for tar that I've seen before include "one may need to pay on deck" , "Sailor - laid on road" , "Black substance in cigarettes" , "Informal sailor or road surfacing material" , "Familiar sailor - what a rat" .)