acknowledgment

noun

1. an act of acknowledging.
2. recognition of the existence or truth of something: the acknowledgment of a sovereign power.
3. an expression of appreciation.
4. a thing done or given in appreciation or gratitude.
5. Law.
   1. a declaration before an official that one has executed a particular legal document.
   2. an official certificate of a formal acknowledging.
   3. public recognition by a man of an illegitimate child as his own.

noun

1. the act of acknowledging or state of being acknowledged
2. something done or given as an expression of thanks, as a reply to a message, etc
3. (plural) an author’s statement acknowledging his use of the works of other authors, usually printed at the front of a book

n.

alternative form of acknowledgement. OED deems it “a spelling more in accordance with Eng. values of letters.”