Nodding acquaintance? (3-3)
I believe the answer is:
yes-man
'nodding acquaintance?' is the definition.
The definition and answer can be both people as well as being singular nouns.
I also know that 'nodding' relates to this answer.
This is all the clue.
Can you help me to learn more?
(Other definitions for yes-man that I've seen before include "Sycophant" , "Flunky" , "He never dissents" .)