HSK 6
乐于
lèyú动
willing (to do sth); to take pleasure in
他一直乐于帮助新同事。
Tā yì zhí lè yú bāng zhù xīn tóng shì.
He has always been willing to help new colleagues.
Say it
Hold the button, say it, then let go.
Other HSK words sharing a character
Also free:
New in the HSK 3.0 word list at level 6.