ac·knowl·edge [ ək nóllij ](past and past participleac·knowl·edged, present participleac·knowl·edg·ing, 3rd person present singularac·knowl·edg·es)
verb
Definition:
1. transitive and intransitive verb admit something: to admit or accept that something exists, is true, or is real
2. transitive and intransitive verb show awareness of something: to respond to something such as a greeting or message to show it has been noticed or received
3. transitive verb show appreciation of something: to show appreciation or express thanks for something such as a letter or gift
4. transitive verb recognize somebody or something legally: to recognize or admit the existence, rights, or authority of somebody or something, especially in a legal context
5. transitive verb thank somebody officially: to officially or publicly recognize somebody's help or work
[15th century. Probably <knowledge after obsolete aknow "recognize, acknowledge" (<know)]