self-assured
adjective
[ ˌsɛlfəˈʃɔːd ]
• confident in one's own abilities or character.
• "a self-assured 16-year-old"
Similar:
self-confident,
confident,
believing in oneself,
positive,
assertive,
assured,
authoritative,
commanding,
self-reliant,
self-possessed,
composed,
poised,