Acting in a way is doing what you're told (8)
I believe the answer is:
behaving
'acting' is the definition.
(behaving is a kind of acting)
'a way is doing what you're told' is the wordplay.
I cannot quite understand how this works, but
'a' is present in the answer.
'way' could be 'n' (Compass direction - North) and 'n' is found within the answer.
'is' could be 'be' and 'be' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for behaving that I've seen before include "acting well" , "what Fats was up to?" , "Conducting (oneself) well" .)