taru-adjective, adverb taking the 'to' particle
Literary or formal expression describing a state of visible happiness or delight. Often used adverbially with と (嬉々として) or as a たる adjective in written language.
彼は嬉々としてその仕事を引き受けた。
He cheerfully took on the task.
子供たちは嬉々とした表情で遊んでいた。
The children were playing with joyful expressions.
Rare variant spelling.
Rarely used kanji form.
Rarely used kanji form.
Reduplication of the kanji 嬉 (joy) to emphasize the state. The reading き is the on'yomi. The exact historical derivation is uncertain, but the form is used in classical and literary Japanese.