Cool (adjective)

1. Having a relaxed, calm demeanor.
2. Having a low temperature.
3. Having a pleasing and refreshing quality.
4. Fashionable and stylish.
5. Excellent or impressive in a way that inspires admiration and approval.

Origin:

The origin of the word cool is uncertain, but it likely evolved from middle english word 'col' meaning 'calm, peaceful' which was later used in jazz slang in the 1920s to mean "fashionable, stylish, unruffled".

Examples:

1. She remained cool even in the face of adversity.
2. The air conditioning makes this room so cool.
3. A cool breeze is blowing across the lake.
4. Cool sneakers are a must for anyone who wants to look stylish.
5. This new app is so cool, you can create animations with ease!