noun
full of vitality; exuberant; effervescent
Describes a state of overflowing energy and high spirits; somewhat literary or emphatic.
彼は気力横溢の若者だ。
He is a young man brimming with vitality.
気力横溢の演説に聴衆は感動した。
The audience was moved by the exuberant speech.
Compound of 気力 (vitality, energy) and 横溢 (overflowing, brimming). The exact historical derivation is uncertain, but the word is formed from standard Sino-Japanese elements.