Definitions

1. verb

to make or become cooler or less hot; to reduce the temperature

“The air conditioner will attemperate the room in a few minutes.”

2. verb (transitive)

to reduce the temperature of something

“The scientist attemperated the solution to a lower temperature before testing.”

3. noun

a person or thing that reduces or moderates the heat of something

“The attemperate was used to cool down the engine before taking it apart for repairs.”