Both Uses

acknowledge
in
Me Before You
(Edited)

I thought perhaps he had been indoors so long that it was all bound to feel a little weird for him, and I decided I was simply not going to acknowledge it.
p. 160.8

acknowledge = express recognition of
Nobody acknowledged Will.
p. 290.9 *

acknowledged = expressed recognition of

Definitions:

(1) (acknowledge as in: acknowledge her or the truth)
express recognition or appreciation of someone or something; or to admit or express something
(2) (meaning too rare to warrant focus)
Specialized senses include sending an "acknowledgement" (letter or other message) to indicate that something was received and the "acknowledgements" section at the beginning of a book where an author recognizes and thanks other people who helped in creating the book or ideas contained in it.