noun, na-adjective
full of energy; highly motivated; full of drive
Describes a person or their state as being brimming with mental energy, motivation, or vitality. Often used in formal or written contexts.
彼はいつも気力旺盛で、仕事に取り組んでいる。
He always tackles his work with great energy and motivation.
気力旺盛な若者たちが新しいプロジェクトを始めた。
The highly motivated young people started a new project.
Compound of 気力 (mental energy, drive) and 旺盛 (vigorous, abundant). The exact historical derivation is uncertain, but the combination is transparently formed from these two Sino-Japanese elements.