Overjoyed (one word not two) means very happy.
No, the word overjoyed is not an adverb.The word overjoyed is an adjective.
overjoyed
She was overjoyed to see the boy.
The root word for "overjoyed" is "joy." The prefix "over-" is added to intensify the feeling of joy.
My dog is normally overjoyed to see me.
i was overjoyed when my team won the trophy
elated
yes
yes
overjoyed
· overjoyed
frantic overjoyed