asentimiento

n. assent, concur, accession

= acknowledgement [acknowledgment], acquiescence.
Ex: Then, without waiting for an acknowledgement, he said, 'Well, I think Albert is too much the union type' and James expressed surprise.
Ex: After decades of inertia and acquiescence, academic researchers are beginning to offer alternatives to the highly inefficient and unfair system of journal publishing in academia.
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* asentimiento con la cabeza = head-nod [head nod], nodding assent.