About to go off such an acquaintance? (7)
I believe the answer is:
nodding
'such an acquaintance?' is the definition.
(as in the phrase nodding aquaintance)
'about to go' is the wordplay.
I cannot quite see how this works, but
'go' could be 'din' (dinning is a kind of going) and 'din' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'off' is the link.
Can you help me to learn more?
(Other definitions for nodding that I've seen before include "Saying yes with head" , "Indicating yes" , "Dozing (off)" , "ready to drop off" , "Not showing much interest in" .)