lactic

American  

[lak-tik] / ˈlæk tɪk /

adjective

1. of, relating to, or obtained from milk.

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lactic British  

/ ˈlæktɪk /

adjective

1. relating to or derived from milk

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Other Word Forms

• nonlactic
  adjective

Etymology

Origin of lactic

First recorded in 1780–90; lact- + -ic

Explanation

Scientists use the word lactic for substances that have to do with milk. Lactic acid is the substance that makes things like yogurt and buttermilk taste sour. The term lactic comes from the French lactique and its Latin root, lac, or "milk." The word is almost always connected to acid — lactic acid, also known as lactate, is the byproduct of a chemical reaction that occurs in milk as it ferments. Lactic acid is also present in our bodies, as it's produced by muscles that are working hard, in our guts, and even in our mouths.

Example Sentences

Yogurt doesn’t just tenderize; it creates a thin lactic crust that browns beautifully in a hot pan.

From Salon • Feb. 24, 2026

“It’s searing pain from all the lactic acid. It floods your system. You blow capillaries in your eyes, you throw up after races,” said Cheek, now an NBC analyst.

From The Wall Street Journal • Feb. 21, 2026

"Keely can be doing certain repetitions, and she's being physically sick from the lactic acid. It's a little bit inhumane at times."

From BBC • Feb. 20, 2026

He added, "We plan to expand international research on kimchi and lactic acid bacteria in relation to immune and metabolic health in the future."

From Science Daily • Dec. 17, 2025

Their shoulders must be rubbed every hour and they must be allowed to shake the lactic acid buildup out of their joints each hour.

From "Woodsong" by Gary Paulsen