UNIVERSEH: The European Space University

Short Definition: 

Any kind of giant cloud that includes miscellaneous gas and dust; especially hydrogen, cosmic dust, and helium located in outer space.

Detailed Definition: 

As the basic components of galaxies, nebulae were stars before they formed. During the formation phase of these stars, the gases released into space initiate a fusion reaction with hydrogen atoms and form the foundations of a new star. Thus, the universe continues to expand.

Etymology:  

Ancient Greek (νεφέλη - nephélē): Cloud

Sample Sentences:

'Today the term nebula generally refers exclusively to the interstellar medium.'

'A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by.'

Translations of Terms/Concepts into Partner Languages:

French:

Nébuleuse

Italian:

Nebulosa

German:

Nebel

Polish:

Mgławica

Turkish:

Nebula

Links to Videos/Articles:

https://spacecenter.org/what-is-a-nebula/

https://spaceplace.nasa.gov/nebula/en/

https://www.space.com/nebula-definition-types

https://www.britannica.com/science/nebula