Confident (adjective)

1. Having or showing self-assurance.
2. Certain of one's own abilities or qualities.
3. Sure of oneself.

Origin:

Mid 17th century: from latin confident- "having trust in", from the verb confidere.

Examples:

1. He appeared confident in his abilities.
2. She was confident in her decision.
3. He is confident that he will succeed.
4. The company is confident in its future.
5. She gave a confident performance.