Acquiescence
The definition of acquiescence is acceptance without protest. It is a legal term used to describe an act where a person knowingly stands by without raising any objection to the infringement of their rights, while someone else unknowingly and without malice aforethought makes a claim on their rights. The person whose rights are infringed loses the ability to make a claim against the infringer, or succeed in an injunction suit due to the infringer's conduct. The term is most generally "permission" given by silence or passiveness. Acceptance or agreement by keeping quiet or by not making objections.
In this case, the word acquiescence is used to acknowledge that Atticus is making no attempt to make Scout go to bed, probably because he is tired, and because he realises that there is a lot that Scout needs to think and talk over.
In this case, the word acquiescence is used to acknowledge that Atticus is making no attempt to make Scout go to bed, probably because he is tired, and because he realises that there is a lot that Scout needs to think and talk over.