乐于 Traditional form: 樂於 Pinyin (reading): lèyú Definitions: willing (to do sth) to take pleasure in Characters: 乐 - cheerful, happy, laughing; music 于 - at, in, on; to, from; alas! Traditional characters: 樂 - cheerful, happy, laughing; music 於 - at, in, on; to, from; alas!