Pronunciation: (ak-nol'ij),[key] —v.t.,-edged, -edg•ing. 1. to admit to be real or true; recognize the existence, truth, or fact of: to acknowledge one's mistakes. 2. to show or express recognition or realization of: to acknowledge an acquaintance by nodding. 3. to recognize the authority, validity, or claims of: The students acknowledged the authority of the student council. 4. to show or express appreciation or gratitude for: to acknowledge a favor. 5. to indicate or make known the receipt of: to acknowledge a letter. 6. to take notice of or reply to: to acknowledge a greeting. 7. Law.to confirm as binding or of legal force: to acknowledge a deed.