be cocksure of (oneself)

To be completely certain of oneself or one's actions, to the point of overconfidence. You seem pretty cocksure of yourself—do you really know how to handle that machine?

Common Names:

Name	Pronounced	Usage
&Aelig;Thelric	-	Anglo-Saxon (Latinized)
Marcia	MAHR-shə (English), MAHR-see-ə (English), MAHR-thyah (Spanish), MAHR-syah (Latin American Spanish)	English, Spanish, Ancient Roman
Ioan	-	Romanian, Welsh, Bulgarian
Waimarie	-	Maori
Mcgraw	[mə'grɔ:]
Tere	TE-re	Spanish