Cocksureness in a sentence as a noun

It didn't help that they think their research backed up their cocksureness, but in reality the research were painfully biased and incorrect.

These people can be insufferable when they are sure they are right and think everyone who is trying to temper their cocksureness is just being negative.

Cocksureness definitions

noun

total certainty or greater certainty than circumstances warrant

See also: certitude overconfidence