Real Dictionary

ticket
A ticket is a small, official piece of paper or card which shows that you have paid to enter a place such as a theatre or a sports ground, or shows that you have paid for a journey.
countable noun: A ticket is an official piece of paper which orders you to pay a fine or to appear in court because you have committed a driving or parking offence.

ticket in American English
any note, memorandum, voucher, etc.
to label or tag with a ticket
noun: a slip, usually of paper or cardboard, serving as evidence that the holder has paid a fare or admission or is entitled to some service, right, or the like

ticket in British English
noun: a piece of paper, cardboard, etc, showing that the holder is entitled to certain rights, such as travel on a train or bus, entry to a place of public entertainment, etc

ticket in Retail
noun: A ticket is a label attached to merchandise showing the price and other details.