補票

to buy or upgrade a ticket after boarding a train, boat etc / to buy a ticket for a show after having sat down in the theater

ticket / ballot / banknote / CL:張|张[zhang1] / person held for ransom / amateur performance of Chinese opera / classifier for groups, batches, business transactions

to repair / to patch / to mend / to make up for / to fill (a vacancy) / to supplement

additional ticket desk / stand-by counter