What does "sunspot" mean?

A region on the sun's surface with a lower temperature than its surroundings and intense magnetic activity.

What is a synonym for "sunspot"?

Common synonyms include: dark solar region, freckles, macula, solar spot.

/ˈsʌnspɒt/ noun

noun ·Rare ·Advanced level

Noun

1
A region on the sun's surface with a lower temperature than its surroundings and intense magnetic activity.
2
a cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field wordnet
3
A random shock in the foreign exchange currency market.

"Most of the surface of the Sun has a temperature of about 5400 degrees C, but in a big sunspot the temperature can drop to about 4000 degrees C."

From sun + spot.