n. 断言, 郑重声明

[ noun ]
a declaration that is made emphatically (as if no supporting evidence were necessary)
<noun.communication>

Asseveration \As*sev`er*a"tion\, n. [L. asseveratio.]
The act of asseverating, or that which is asseverated;
positive affirmation or assertion; solemn declaration.

Another abuse of the tongue I might add, -- vehement
asseverations upon slight and trivial occasions. --Ray.