acknowledge

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To admit the existence, reality, or truth of.
2. v. To recognize as being valid or having force or power.
3. v. To express recognition of: acknowledge a friend's smile.
4. v. To express thanks or gratitude for.
5. v. To report the receipt of: acknowledge a letter.
6. v. Law To accept or certify as legally binding: acknowledge a deed.

Century Dictionary and Cyclopedia

1. To admit or profess a knowledge of; avow to be within one's knowledge or apprehension; own to be real or true; recognize the existence, truth, or fact of: as, to acknowledge God, or the existence of or belief in a God; to acknowledge the rights of a claimant.
2. To express or manifest perception or appreciation of; give evidence of recognizing or realizing: as, to acknowledge an acquaintance by bowing; to acknowledge a favor or one's faults.
3. To own the genuineness of; own as binding or of legal force: as, to acknowledge a deed.
4. To admit or certify the receipt of; give information of the arrival of: as, to acknowledge a letter or a remittance.

Wiktionary

1. v. transitive To admit the knowledge of; to recognize as a fact or truth; to declare one's belief in; as, to acknowledge the being of a God.
2. v. To own or recognize in a particular quality, character or relationship; to admit the claims or authority of; to give recognition to.
3. v. To own with gratitude or as a benefit or an obligation; as, to acknowledge a favor.
4. v. To notify receipt, as of a letter.
5. v. To own as genuine or valid; to assent to, as a legal instrument, to give it validity; to avow or admit in legal form; as, to acknowledge a deed.

GNU Webster's 1913

1. v. To own or admit the knowledge of; to recognize as a fact or truth; to declare one's belief in.
2. v. To own or recognize in a particular character or relationship; to admit the claims or authority of; to give recognition to.
3. v. To own with gratitude or as a benefit or an obligation.
4. v. To own as genuine; to assent to, as a legal instrument, to give it validity; to avow or admit in legal form.

WordNet 3.0

1. v. express recognition of the presence or existence of, or acquaintance with
2. v. report the receipt of
3. v. accept as legally binding and valid
4. v. express obligation, thanks, or gratitude for
5. v. declare to be true or admit the existence or reality or truth of
6. v. accept (someone) to be what is claimed or accept his power and authority