Mole

How to spell mole

4 letters · 1 syllable

How to pronounce mole

What does mole mean?

1. nounA small burrowing mammal with velvety fur and powerful digging forefeet that lives mostly underground.
2. nounA small dark pigmented spot or raised mark on the skin.
3. nounA spy or informant who works secretly inside an organisation while pretending to be loyal to it.
4. nounThe SI unit for amount of substance, equal to a fixed very large number of particles.

Mole in a sentence

• A mole had pushed up a ridge of soil across the lawn overnight.

• The doctor examined a mole on her shoulder to check it had not changed shape.

• Investigators suspected a mole had been leaking confidential files to a rival firm.

• The student calculated how many grams made up one mole of carbon.

• The gardener set traps because a mole was tunnelling under the flower beds.

• He has a small dark mole just below his left eye.

Where does mole come from?

Language of origin: Germanic

English 'mole' is really several different words that collapsed into one spelling. The burrowing-animal sense, which is the most familiar, came into late Middle English around the 1300s, probably shortened from an older compound and related to Middle Dutch 'mol' and Middle Low German 'molle', words for the same creature. The skin-blemish sense is a separate and much older native word: Old English 'mal' meant a spot, mark, or stain on the skin, and it is connected to the Germanic root that also gave the German 'Mal', meaning a mark. The espionage sense grew naturally out of the animal idea of something working secretly underground, and it was popularised in the twentieth century, especially through spy fiction. Two more unrelated 'moles' arrived from elsewhere: the chemistry unit was borrowed in the early 1900s from German 'Mol', a clipping of 'Molekul' (molecule), and the rich Mexican sauce comes from Nahuatl 'molli', simply meaning sauce. Because all these threads landed on the same three letters, the spelling itself is easy; the difficulty is purely keeping the meanings straight.

How the word is built

• mole (a single, unanalysable root; the animal name has no prefix or suffix)