mole

1 of 6

noun (1)

ˈmōl 

: a pigmented spot, mark, or small permanent protuberance on the human body

especially : nevus

mole

2 of 6

noun (2)

1

: any of numerous burrowing insectivores (especially family Talpidae) with tiny eyes, concealed ears, and soft fur

2

: one who works in the dark

3

: a machine for tunneling

4

: a spy (such as a double agent) who establishes a cover long before beginning espionage

broadly : one within an organization who passes on information

mole

3 of 6

noun (3)

: an abnormal mass in the uterus especially when containing fetal tissues

mole

4 of 6

noun (4)

1

: a massive work formed of masonry and large stones or earth laid in the sea as a pier or breakwater

2

: the harbor formed by a mole

mole

5 of 6

noun (5)

ˈmōl 

variants or less commonly mol

plural moles

: the base unit of amount of pure substance in the International System of Units that is defined as having exactly 6.02214076 x 10²³ indivisible units (such as atoms or molecules) of that substance

First you would need to measure out one mole of salt. Remember that one mole of a compound equals its relative molecular mass in grams, so to obtain one mole of sodium chloride you would weigh out 58.5 g …

—John Atkinson and Carol Hibbert

one mole of helium contains 4 grams

mole

6 of 6

noun (6)

mo·​le ˈmō-lā 

: a spicy sauce made with chiles and usually chocolate and served with meat

Synonyms

Noun (2)

• agent
• asset
• emissary
• intelligencer
• operative
• spook
• spy
• undercover

Examples of mole in a Sentence

Noun (2)

for years we have had a mole in the enemy's national intelligence agency

Recent Examples on the Web

Noun

As his search continues, the mole is selling the top secret information to the highest bidder and gathering enough resources to build a big enough bomb to blow up Manhattan. —Jordan Moreau, Variety, 25 Dec. 2024

Helen, in her dual role as politician’s wife and mole, feels twice the pressure to keep up appearances. —Inkoo Kang, The New Yorker, 23 Dec. 2024

Known for mole poblano, James Beard award finalist chef Maria Meza works along with her two sons, general manager Joaquin and bar manager, Marco. —Pat Doherty, Travel + Leisure, 22 Dec. 2024

One study even used photos of the same person—modified to include either a scar, misaligned teeth, thicker eyebrows or a mole—and tested whether prosocial descriptions enhanced beauty ratings, regardless of physical features. —Mark Travers, Forbes, 22 Dec. 2024

Word History

Etymology

Noun (1)

Middle English, from Old English māl; akin to Old High German meil spot

Noun (2)

Middle English; akin to Middle Low German mol

Noun (3)

Middle English, from Latin mola mole, literally, mill, millstone — more at mill

Noun (4)

Middle French, from Old Italian molo, from Late Greek mōlos, from Latin moles, literally, mass, exertion; akin to Greek mōlos exertion

Noun (5)

German Mol, short for Molekulargewicht molecular weight, from molekular molecular + Gewicht weight

Noun (6)

Mexican Spanish, from Nahuatl mōlli sauce

First Known Use

Noun (1)

14th century, in the meaning defined above

Noun (2)

14th century, in the meaning defined at sense 1

Noun (3)

15th century, in the meaning defined above

Noun (4)

circa 1548, in the meaning defined at sense 1

Noun (5)

1902, in the meaning defined above

Noun (6)

1882, in the meaning defined above

Phrases Containing mole

• mole cricket
• mole rat
• naked mole rat
• star-nosed mole

Kids Definition

mole

1 of 3 noun

ˈmōl 

: a small usually brown and sometimes slightly raised permanent spot on the skin

mole

2 of 3 noun

: any of numerous burrowing mammals with tiny eyes, concealed ears, and soft fur that eat insects

mole

3 of 3 noun

: a pier made of heavy solid material (as concrete or stone) that protects a harbor from rough seas

Etymology

Noun

Old English māl "spot on the skin"

Noun

Middle English mole "burrowing animal"

Noun

from early French mole "stone pier," from early Italian molo (same meaning), derived from Latin moles, literally "a mass"

Medical Definition

mole

1 of 3 noun

ˈmōl 

: a pigmented spot, mark, or small permanent protuberance on the human body

especially : nevus

mole

2 of 3 noun

: an abnormal mass in the uterus:

a

: a blood clot containing a degenerated fetus and its membranes

b

: hydatidiform mole

mole

3 of 3 noun

variants also mol

ˈmōl 

: the base unit in the International System of Units for the amount of pure substance that contains the same number of elementary entities as there are atoms in exactly 12 grams of the isotope carbon 12

a mole of photons

a mole of sodium chloride