na-adjective, noun which may take the genitive case particle 'no', taru-adjective, adverb taking the 'to' particle
full of confidence; brimming with self-confidence
Describes a person who is extremely confident, often to the point of appearing self-assured or even cocky. Can be used positively or negatively depending on context.
彼は自信満々でプレゼンに臨んだ。
He approached the presentation full of confidence.
自信満々な態度が時に反感を買うこともある。
A brimming-with-confidence attitude can sometimes invite resentment.
Compound of 自信 (self-confidence) and 満々 (brimming, full of), a reduplicative form of 満 (full).