Latin word libenter comes from Latin libens, Latin -ter (-ly; used to form adverbs from adjectives.)
libens (Latin)
Glad, cheerful, merry. Ready, willing, eager. With pleasure, with good will.
-ter (Latin)
-ly; used to form adverbs from adjectives.
libenter (Latin)
Gladly, cheerfully. Willingly, eagerly. With vigour, with enthusiasm.