linearly
adv.in a straight line or in a way that follows a simple, direct pattern. You use this to describe things that increase or decrease at a steady rate.
adv.in a straight line or in a manner that follows a direct, proportional relationship. Often describes mathematical functions or physical processes where the output is directly proportional to the input.
“The cost of the tickets increases linearly with the number of people.”
“The scientist observed that the temperature of the liquid rose linearly as the heat was applied.”
“While the initial growth of the bacteria was linearly proportional to the available nutrients, the rate eventually slowed as the environment became saturated with waste products.”
Usage linearly increase
“The story unfolds linearly, but your choices still matter in the complex missions.”
From linear + -ly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.