Packet

A small pack or package; a little bundle or parcel; as, a packet of letters.

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.

To make up into a packet or bundle.

To send in a packet or dispatch vessel.

To ply with a packet or dispatch boat.

(computer science) a message or message fragment