noun A small pack or package; a little bundle or parcel
Don't throw the crisp packet on the floor!
noun Originally, a vessel employed by government to convey dispatches or mails; hence, a vessel employed in conveying dispatches, mails, passengers, and goods, and having fixed days of sailing; a mail boat. Packet boat, ship, vessel (Wikipedia).
noun A specimen envelope containing small, dried plants or containing parts of plants when attached to a larger sheet.
noun A small fragment of data as transmitted on some types of network, notably Ethernet networks (Wikipedia).
noun A protocol data unit of the Internet Protocol.
noun A message sent over a transport layer protocol.