Learner's definition of DECLARATION
1 : the act of making an official statement about something : the act of declaring something
2 [count] : something that is stated or made known in an official or public way 3 [count] : a document that contains an official statement : a document that makes a declaration — usually singular
The museum has a copy of the country's declaration of independence/sovereignty.
the American Declaration of Independence
Every 4th of July, we read a copy of the Declaration. [=the U.S. Declaration of Independence]