galacto-

Galacto- is a combining form used like a prefix meaning “milk.” It is occasionally used in medical terms, especially in anatomy and pathology.

Galacto- comes from Greek gála (stem galakt-), meaning “milk.” The Latin cognate of gála is lac (stem lact-), also meaning “milk,” which is the source of lactose, latte, and perhaps even lettuce. To learn more, check out our Words That Use articles on the combining forms lact-, lacti-, and lacto-.

What are variants of galacto-?

When combined with words or word elements that begin with a vowel, galacto- becomes galact-, as in galactosis. Want to know more? Read our Words That Use galact- article.

A medical term that uses the form galacto- is galactorrhea, “an abnormally abundant flow of milk in a lactating woman.”

We know galacto- means “milk,” and the -rrhea portion of the word refers to “flow” or “discharge,” from Greek rhoía. Galactorrhea literally translates to “milk flow.”

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

• galactobolic
• galactocele
• galactokinase
• galactolipid
• galactometer
• galactophore

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

• gamo-
• gastro-
• lacto-

The combining form -meter means “measure” and is used to denote instruments that measure. With this in mind, what does galactometer literally mean?