I. dem‧o¹ /ˈdeməʊ $ -moʊ/ noun (plural demos) [countable]
[Date: 1900-2000; Origin: demonstration]

1. a recording containing an example of someone’s music that is sent to a record company so that they can decide whether to produce it or not:
a demo tape

2. British English informal an event at which a large group of people publicly protest about something Synonym : demonstration:
pro-independence demos

3. an explanation of how something works Synonym : demonstration

4.
a) American English an example of a product that is used to show what it is like or how it works:
demo homes on the new development
b) a computer program that shows what a new piece of software will be able to do when it is ready to be sold:
Click here to download a demo of the new version of our personal finance software.

[TahlilGaran] Dictionary of Contemporary English ▲

II. demo² verb [transitive] informal
to show or explain how something works or is done, especially new computer equipment Synonym : demonstrate:
They’re going to demo some of the new software at this year’s Mac convention.

[TahlilGaran] Dictionary of Contemporary English ▲