1. to open (transitive or intransitive)
2. (of ships, vehicles, troops etc) to start
3. to turn on; to put in operation; to operate; to run
4. to boil
5. to write out (a prescription, check, invoice etc)
6. (directional complement) away; off
7. carat (gold)
8. abbr. for Kelvin, 开尔文 Kāiěrwén
9. abbr. for 开本 kāiběn, book format

classifiers: 張, 個