lacto-

1. a combining form meaning “milk,” used in the formation of compound words ( lactometer ); specialized in chemical terminology to mean “lactate,” or “lactic acid.”

lacto-

combining_form

1. indicating milk

   lactobacillus

Word History and Origins

Origin of lacto-¹

< Latin lact- (stem of lac milk) + -o-

Word History and Origins

Origin of lacto-¹

from Latin lact-, lac milk

Example Sentences

For instance, besides abstaining from meat, poultry and seafood, lacto vegetarians also do not eat eggs but do consume dairy products.

From Washington Post

The techniques they harness in the lab can span months; in the guide they span pages – 14 in the case of the very first recipe, lacto plums – even though it requires just ripe plums and non-iodized salt.

From The Guardian

Lacto is short for lactobacillus, the bacteria found in many sour beers, and also for the tangy acid it produces.

From Wall Street Journal

“If you’re bringing in hoppiness, you can have a problem with the lacto souring,” McGarvey explains, because of a reaction between hops and the bacteria.

From Washington Post

Her mother saved every penny for ballet lessons and after the war they came to London, where Audrey danced in the chorus of whatever shows would take her, earning a little extra as a model in newspaper ads for Lacto calamine, a “skin food”.

From The Guardian

Words That Use lacto-

What does lacto- mean?

Lacto- is a combining form used like a prefix meaning “milk.” In terms from chemistry, it used to specifically mean “lactate” or “lactic acid.” It is often used in scientific and medical terms.

Lacto- comes from Latin lac (stem lact-), meaning “milk.” The Latin cognate of lac is gála (stem galakt-), also meaning “milk,” which is the source of galaxy. To learn more, check out our Words That Use articles on galacto- and galact-.

What are variants of lacto-?

When combined with words or word elements that begin with a vowel, lacto- becomes lact-, as in lactose.

A less common variant of lacto-, when combined with some words or word elements that begin with a consonant, is lacti-, as in lactifuge.

Want to know more? Read our Words That Use articles about lact- and lacti-.

Examples of lacto-

One example of a scientific term that uses the form lacto- is lactogen, “an agent that stimulates lactation.”

The lacto- part of the word means “milk,” as we already know. The second part of lactogen is the combining form -gen, which means “that which produces.” Lactogen literally translates to “that which produces milk.”

What are some words that use the combining form lacto-?

• lactobacillus
• lactocele
• lactoferrin
• lactoflavin
• lactogenesis
• lactometer

What are some other forms that lacto- may be commonly confused with?

• galact-
• galacto-

Break it down!

The combining form -cele means “tumor.” With this in mind, what does lactocele literally mean?