Verbally thanks sailor (3)
I believe the answer is:
tar
'sailor' is the definition.
(slang term for a sailor)
'verbally thanks' is the wordplay.
I cannot quite understand how this works, but
'thanks' could be 'ta' (UK informal version of 'thank you') and 'ta' is present in the answer.
A single letter 'r' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tar that I've seen before include "prepare for feathers?" , "Sailor (colloq.)" , "One sails on sea" , "Cigarette residue - old word for sailor" , "Sticky black stuff" .)