開く， 空く， 明く， あく
1. to open (e.g. doors)
2. to open (e.g. business, etc.)
3. to be empty
4. to be vacant, to be available, to be free
5. to be open (e.g. neckline, etc.)
6. to have been opened (of one's eyes, mouth, etc.)
7. to come to an end
8. to open (one's eyes, ...
开、(门)开了；敞开(例如领口等)；(眼)睁开；(嘴)张开