Completely empty or vacant; having nothing inside. Can be used literally (a container) or figuratively (mind or heart being empty).
財布が空っぽで、昼ごはんを買うお金がない。
My wallet is empty; I don't have money to buy lunch.
部屋を出るときに段ボールが空っぽになっているか確認した。
When leaving the room, I checked that the cardboard box was empty.
彼の頭はテレビばかり見ていて、知識が空っぽだとは言えないが心配だ。
I can't say his head is entirely empty since he watches TV a lot, but it's worrying.
朝の冷蔵庫は空っぽで、買い物に行かないといけない。
The fridge was empty in the morning; I need to go shopping.