Definition of "Acknowledge" :
verb: accept (someone) to be what is claimed or accept his power and authority
"The Crown Prince was acknowledged as the true heir to the throne."
verb: accept as legally binding and valid
"Acknowledge the deed."
verb: declare to be true or admit the existence or reality or truth of
"She acknowledged that she might have forgotten."
verb: express obligation, thanks, or gratitude for
"We must acknowledge the kindness she showed towards us."
verb: report the receipt of
"The program committee acknowledged the submission of the authors of the paper."
verb: express recognition of the presence or existence of, or acquaintance with
"He never acknowledges his colleagues when they run into him in the hallway."