Rāhula (English spelling) Rahula

Japanese: Rāhula（英語表記）Rahula

…Also, when he was leaving the castle through the east, west, south, and north gates, he encountered old people, sick people, dead people, and monks, and foresaw the path he should take. After marrying Yashodara and giving birth to a son, Rāhula, he escaped the castle one night accompanied by his beloved horse Kantaka and his charioteer Chandaka, and devoted himself to the life of a sramana (monk) in the kingdom of Magadha. He was not satisfied with the instruction in Zen from two sages, and after six years of asceticism without success, he regained his strength by eating milk porridge provided by the village girl Sujata, entered into meditation at the roots of the Ashbhatta tree on the banks of the Neranjara River, and finally attained enlightenment (enlightenment) and became a Buddha (an enlightened person) (the Ashbhatta tree was later called the Bodhi tree). …

From "The Ten Great Disciples"

…In the First Council, the Vinaya (rules of living for the Buddhist order) was compiled based on his memory. (9) Rahula (Rahula) in Sanskrit. Also written as Ragna. …

*Some of the terminology explanations that mention "Rāhula" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…また城の東･西･南･北の門から外出しようとして老人，病人，死人，出家者に遭遇し，自分の進むべき道を予見する。ヤショーダラーを妃とし，一子ラーフラRāhulaをもうけたあと，一夜，愛馬カンタカと御者チャンダカを従えて城を脱出し，マガダ国で沙門(修道者)の生活に身を投ずる。2仙人に禅の指導をうけたが満足せず，6年苦行に励んだが得るところなく，村娘スジャータの提供する乳粥で体力をつけ，ネーランジャラー河畔のアシュバッタ樹の根方で瞑想に入り，ついに菩提(悟り)を得て仏陀(悟った人)となった(アシュバッタ樹はこれよりのち菩提樹と呼ばれる)。…