mare

B2 · Upper Intermediate Countable noun British English · Informal

n. a very difficult, annoying, or embarrassing situation.

n. a nightmare or highly frustrating experience; a shortening of 'nightmare'.

“I had a total mare at work today when the computer system crashed.”

“The goalkeeper had a complete mare, conceding three soft goals in the first half before being substituted at the break.”

C1 · Advanced Countable noun Science Technical

n. a large, dark, flat area on the surface of the moon.

n. a large, dark, basaltic plain on Earth's Moon, formed by ancient volcanic eruptions.

“The Sea of Tranquility is a famous mare where the first astronauts landed.”

“Early astronomers mistakenly identified each lunar mare as a literal sea, unaware that these dark patches were actually solidified lava flows.”