acknowledge

Concise Oxford English Dictionary © 2008 Oxford University Press:
acknowledge/əkˈnɒlɪʤ/

▶verb

• 1 accept or admit the existence or truth of.

• 2 confirm receipt of or gratitude for.

• 3 greet with words or gestures.

– derivatives
acknowledgeable adjective.

– origin C15: from the obs. ME verb knowledge, influenced by obs. acknow ‘acknowledge, confess’.