ak-nol'-ej (gignosko): To declare that one recognizes the claims of a person or thing fully established. Both in Old Testament and New Testament expressed by various forms of the word "know" (Pr 3:6; Isa 61:9; Col 2:2 the King James Version). The Psalmist (Ps 32:5) "acknowledged" his sin, when he told God that he knew the guilt of what he had done. The Corinthians (2Co 1:14) "acknowledged" Paul and his companions when they formally recognized their claims and authority.
The International Standard Bible Encyclopedia
Acknowledge
The International Standard Bible Encyclopedia, James Orr (1915). Public domain, from the CrossWire SWORD module.