long ‧ ing ‧ ly /ˈlɒŋɪŋli $ ˈlɒːŋ-/ BrE AmE adverb
in a way that shows that you want someone or something very much:
She thought longingly of returning to Paris.
look/gaze longingly at somebody/something
He looked longingly at the tray of cakes.
—longing adjective