Subduing, thanks to an old Chinese (6)
I believe the answer is:
taming
'subduing' is the definition.
('tame' can be a synonym of 'subdue')
'thanks to an old chinese' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'to' says to put letters next to each other.
'an old chinese' becomes 'ming' (Chinese dynasty. I am not sure about the 'old' bit.).
'ta'+'ming'='TAMING'
Can you help me to learn more?
(Other definitions for taming that I've seen before include "Reducing an animal to a domestic state" , "Subjugation" , "Breaking" , "Overcoming wildness" , "The ...... of the Shrew (Shakespeare)" .)