taru-adjective, adverb taking the 'to' particle
high-spirited; in high spirits
Literary taru-adjective/adverb; almost always appears in the fixed expression 意気軒昂 (いきけんこう), meaning 'in high spirits' or 'full of vigor'. Rarely used independently.
See also: 意気軒昂
彼は意気軒昂として新たな事業に乗り出した。
He embarked on a new venture in high spirits.
「軒昂」は「意気軒昂」という成句の中
軒昂 is almost always used within the set phrase 意気軒昂.
The kanji 軒 (eaves) and 昂 (rise) combine to suggest a spirited, elevated mood. The exact historical derivation is uncertain; the word is now fossilized in the compound 意気軒昂.