Wiktionary
n. (context computing English) a microcomputer powered by batteries with an integral display screen and integral input device (such as a keyboard) that can be used on the move
WordNet
n. a personal computer that can easily be carried by hand
Wikipedia
A portable computer is a computer that is designed to be moved from one place to another and includes a display and keyboard. Portable computers, by their nature, are generally microcomputers. Portable computers, because of their size, are also commonly known as 'Lunchbox' or 'Luggable' computers. They can also be called a 'Portable Workstation' or 'Portable PC'.
These are distinct from desktop replacement computers in that they are usually constructed from full-specification desktop components, and do not incorporate features associated with laptops or mobile devices. The principal advantage of a portable computer versus a laptop or other mobile computing device is the use of standard motherboards or backplanes providing plug-in slots for add-in cards. This allows mission specific cards such as test, A/D, or communication protocol (IEEE-488, 1553) to be installed. Portable computers also provide for more disk storage by using standard 3-1/2" drives and providing for multiple drives.
Usage examples of "portable computer".
They'd just rolled off the tarmac when Price mated his portable computer with the aircraft's phone system.
On the final morning at the Beta campsite, before she and the others had set out to look for Takagishi, Nicole had transmitted all the notes in her own portable computer in Rama through the networking system to the desktop in her room on the Newton.
I made myself busy with unpacking and transferred the notes from the portable computer to my work machine.
The e-mail address was accessed through a major provider of Internet service, but it could belong to anyone with a portable computer and the few dollars a month needed to buy such an address.
While the Secretary-designate chatted with Mark Gant, the latter's portable computer open and operating in front of him, the table to their left groaned and crashed, spilling the pile of books to the floor, to the collective gasp of everyone in the room.
A little portable computer with a built-in modem watched the phone, in case Bobby called.
Before I left, I made certain that there was a reasonably accurate graphics drawing of Richard stored in my portable computer.
He was using a small side table until they got the desk apart, with his desk lamp and his portable computer on top.
He handed it to Newman, who slid it into the CD slot on his portable computer and transferred the information to his hard drive.