An agreeable chap (3-3)

I believe the answer is:
yes-man
'an agreeable chap' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'agreeable chap' is the wordplay.
'agreeable' becomes 'yes' (I can't justify this - if you can you should give a lot more credence to this answer).
'chap' becomes 'man' (chap can mean a man).
'yes'+'man'='YES-MAN'
Can you help me to learn more?
(Other definitions for yes-man that I've seen before include "Flunky" , "He never dissents" , "Sycophant" .)
