mu

¹ American  

[myoo, moo] / myu, mu /

noun

1. the 12th letter of the Greek alphabet (M, μ).

2. the consonant sound represented by this letter.

3. micron.

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Mu ² American  

[myoo, moo] / myu, mu /

noun

1. another name for Lemuria.

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MU ¹ British  

abbreviation

1. Musicians' Union

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mu ² British  

/ mjuː /

noun

1. the 12th letter in the Greek alphabet (Μ, μ), a consonant, transliterated as m

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mu ³ British  

abbreviation

1. Mauritius

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Etymology

Origin of mu

First recorded in 1895–1900, mu is from the Greek word mŷ

Example Sentences

The studies focus on a group of experimental pain-relieving compounds that act on mu opioid receptors.

From Science Daily • Jan. 6, 2026

However, naltrexone, in both short- and long-acting forms, has the opposite pharmacology: it antagonizes mu receptors, occupying them without activating them.

From Scientific American • Sep. 13, 2023

This part is called il mu, which can be translated as “line dance” or “one dance.”

From New York Times • Jul. 12, 2023

Such mutations were flagged as errors when scientists, including Fauver, tried to upload their mu sequences to GISAID, an international repository of viral genomes used to keep tabs on new variants.

From Seattle Times • May 4, 2022

I abandoned my beautiful mah jong table of hong mu.

From "The Joy Luck Club" by Amy Tan