To send a package or letter by Federal Express, or a competitor.
"The shipment was sent via fedex, an alternative spelling often used in informal notes."
Alternative form of FedEx
In plain English: To FedEx something means to send it quickly using that specific delivery company's fast shipping service.
"I need to FedEx this package by tomorrow morning so it arrives before the deadline."
Federal Express, a package express company.
"I used FedEx to ship my birthday gift so it would arrive quickly."
FedEx is a blend of the words "federal" and "express." It was shortened from the company's original full name, Federal Express.