mole

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole1 /məʊl/

▶noun

• 1 a small burrowing mammal with dark velvety fur, a long muzzle, and very small eyes, feeding mainly on worms and grubs. [Talpa europaea and other species.]

• 2 a spy who gradually achieves an important position within the security defences of a country.

  ■ a person within an organization who reveals confidential information.

– origin ME: from the Gmc base of MDu. and Mid. Low Ger. mol.

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole2 /məʊl/

▶noun a small dark blemish on the skin caused by a high concentration of melanin.

– origin OE māl ‘discoloured spot’, of Gmc origin.

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole3 /məʊl/

▶noun a large solid structure serving as a pier, breakwater, or causeway.

■ a harbour formed by a mole.

– origin C16: from Fr. môle, from L. moles ‘mass’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole4 /məʊl/ (abbrev.: mol)

▶noun Chemistry the SI unit of amount of substance, equal to the quantity containing as many elementary units as there are atoms in 0.012 kg of carbon-12.

– origin early 20th cent.: from Ger. Mol, from Molekul ‘molecule’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole5 /məʊl/

▶noun Medicine an abnormal mass of tissue in the uterus.

– origin ME: from Fr. môle, from L. mola in the sense ‘false conception’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
mole6 /ˈməʊleɪ/

▶noun a highly spiced Mexican savoury sauce containing chilli peppers and chocolate.

– origin Mex. Sp., from Nahuatl molli ‘sauce, stew’.