1. To show that one has noticed some fact or event
2. To acknowledge the receipt of; SYN. receipt.
3. To discern; SYN. recognize, know.
4. To express obligation for; SYN. recognize.
5. Declare to be true or admit the existence or reality or truth of
6. Report the receipt of
7. Express recognition of the presence or existence of, or acquaintance with
8. Accept as legally binding and valid
9. Accept (someone) to be what is claimed or accept his power and authority