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
Adam	['ædəm]
Hephzibah	HEF-zi-bə (English), HEP-zi-bə (English)	Biblical
Rok	-	Slovene
Arijana	-	Croatian
Kasper	KAHS-per (Polish, Swedish), KAHS-pər (Dutch)	Polish, Dutch, Swedish, Norwegian, Danish
Evangelija	-	Macedonian