Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
For example, look at Olympus Mons, the largest volcano on the planet.
Source: https://www.baltimoregaylife.com/everything-you-need-to-know-about-mars-our-neighboring-red-planet/