godan verb (-mu), intransitive verb
be in high spirits; be eager; be encouraged; cheer up
Intransitive verb for becoming spirited, eager, or encouraged. In modern Japanese it is especially common in the te-form 勇んで, meaning doing something eagerly or in high spirits.
子どもたちは勇んで遠足に出かけた。
The children set off for the excursion in high spirits.
選手たちは大きな声援に勇んだ。
The players were encouraged by the loud cheers.