asseveration
NounWordNet 3.0
Webster's Dictionary (GCIDE)
Asseveration \As*sev`er*a"tion\, n. [L. asseveratio.] The act of asseverating, or that which is asseverated; positive affirmation or assertion; solemn declaration. [1913 Webster]
Another abuse of the tongue I might add, -- vehement asseverations upon slight and trivial occasions. --Ray. [1913 Webster]