inversely
adv.in a way that is the opposite of something else. You use this when two things change in the opposite direction — if one goes up, the other goes down.
adv.in a manner that is opposite or contrary to a given standard or expectation. Often describes a mathematical or physical relationship where an increase in one variable results in a decrease in another.
“The two variables are inversely related.”
“As the temperature rises, the amount of water vapor in the air increases inversely.”
“The economic theory suggests that as the supply of a luxury good increases, its perceived value to the consumer decreases inversely, a principle often observed in the diamond market.”
Usage inversely relate
From inverse + -ly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.