From WordNet (r) 3.0 (2006) :
desktop
n 1: the top of a desk
2: (computer science) the area of the screen in graphical user
interfaces against which icons and windows appear [syn:
background, desktop, screen background]
From The Free On-line Dictionary of Computing (30 December 2018) :
desktop
1. In a WIMP graphical user interface,
the visual representation of a real desktop (the top surface
of a piece of furniture) with documents, folders and a rubbish
bin arranged on it. The user manipulates files on the
computer by using a mouse to click and drag their
representations ({icons) on the desktop.
The WIMP interface and desktop metaphor was invented at Xerox
PARC and popularised by the Apple Macintosh.
2. desktop computer.
(2007-09-12)