Having or showing confidence and poise. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "self-assured" in a sentence
"He started to seem more self-assured and more likable."
"Rabbi Knobel—a short, self-assured man wearing glasses, a close-cropped beard, and a white robe with a gold-embroidered stole—then takes his place at the podium."
"He has a self-assured manner that borders on smugness, and his deep voice fills the sanctuary authoritatively as he emphatically delivers his sermon."