AskDefine | Define walnut

Dictionary Definition



1 nut of any of various walnut trees having a wrinkled two-lobed seed with a hard shell
2 hard dark-brown wood of any of various walnut trees; used especially for furniture and paneling
3 any of various trees of the genus Juglans [syn: walnut tree]

User Contributed Dictionary



walhhnutu, from ( > Welsh) + *|hnut- ( > nut). Cognate with Dutch walnoot, German Walnuss, Swedish valnöt.


  • (US) /ˈwɑlnət/
  • (UK) /ˈwɔ:lnʌt/


  1. A hardwood tree of the genus Juglans.
  2. The nut of the walnut tree.
  3. The wood of the walnut tree.
  4. (colour) A dark brown colour, the colour of walnut wood.
    walnut colour:   




  1. (colour) Having a dark brown colour, the colour of walnut wood.



See also

Extensive Definition

Walnuts (genus Juglans) are plants in the family Juglandaceae. They are deciduous trees, 10 - 40 meters tall (about 30-130 ft.), with pinnate leaves 200 - 900 millimetres long (about 7-35 inches), with 5 - 25 leaflets; the shoots have chambered pith, a character shared with the wingnuts (Pterocarya) but not the hickories (Carya) in the same family.
The 21 species in the genus range across the north temperate Old World from southeast Europe east to Japan, and more widely in the New World from southeast Canada west to California and south to Argentina. The Latin name ,Juglans, derives from ,Jovis glans, "Jupiter's acorn": figuratively, a nut fit for a god.
The word walnut derives from Old English wealhhnutu, literally "foreign nut", wealh meaning "foreign" (wealh is akin to the terms Welsh and Vlach; see *Walha and History of the term Vlach). The walnut was so called because it was introduced from Gaul and Italy. The previous Latin name for the walnut was nux Gallica, "Gallic nut".


The walnut shell has a wide variety of uses. It is commonly used as an organic abrasive, to polish and clean a number of different materials. Black walnut shell is the hardest of the walnut shells, and therefore has the highest resistance to break-down. It is environmentally friendly and can be recycled. A 2006 study published in the Journal of the American College of Cardiology found that eating walnuts after a meal high in unhealthy fats can reduce the damaging effects of such fats on blood vessels. Researchers from Barcelona's Hospital Clinic conducted a study on 24 adult participants, half of whom had normal cholesterol levels, and half of whom had moderately high levels of cholesterol. Each group was fed two high-fat meals of salami and cheese, eaten one week apart. During one meal, the researchers supplemented the food with five teaspoons of olive oil. The researcher added eight shelled walnuts to the other meal, the following week.
Tests after each meal showed that both the olive oil and the walnuts helped reduce the onset of dangerous inflammation and oxidation in the arteries after the meals, which were high in saturated fat. However, unlike the olive oil, the walnuts also helped the arteries maintain their elasticity and flexibility, even in the participants with higher cholesterol.
Lead researcher Dr. Emilio Ros said walnuts' protective effects could be because the nuts are high in antioxidants and ALA, a plant-based omega-3 fatty acid. Walnuts also contain arginine, which is an amino acid that the body uses to produce nitric oxide, necessary for keeping blood vessels flexible.
The latest scientific development has revealed that the plant leaves have the function of reducing fasting blood sugar (FBS) in diabetic rats, of which beta cells could be regenerated, indicating the promising future of the plant for medicinal use.

Walnut extract and Alzheimer's

A 2004 study by the NYS Institute for Basic Research in Developmental Disabilities (OMRDD) found that walnut extract was able to inhibit and defibrillize (break down) fibrillar amyloid beta protein - the principal component of amyloid plaques in the brains of patients with Alzheimer's. The study looked at the effect of walnut extract on amyloid beta protein fibrillization by Thioflavin T fluorescence spectroscopy and electron microscopy. Similarly, in a study done at Baldwin-Wallace College in Berea, Ohio it was found that two of its major components in walnuts, gallic and ellagic acid, act as "dual-inhibitors" of the enzyme acetylcholinesterase which, in association with amyloid-ß, inhibits protein aggregation, and will also inhibit the site of acetylcholinesterase responsible for the breakdown of acetylcholine.
These results suggest that walnuts may reduce the risk or delay the onset of Alzheimer's disease by maintaining amyloid beta protein in the soluble form and prevent the breakdown of acetylcholine.



walnut in Asturian: Nuez
walnut in Bulgarian: Орех
walnut in Danish: Valnød-slægten
walnut in German: Walnüsse
walnut in Modern Greek (1453-): Καρυδιά (φυτό)
walnut in Spanish: Juglans
walnut in Esperanto: Juglando (genro)
walnut in Persian: گردو
walnut in French: Noyer
walnut in Galician: Nogueira
walnut in Croatian: Orah
walnut in Italian: Juglans
walnut in Latin: Iuglans
walnut in Latvian: Valrieksts
walnut in Hungarian: Dió
walnut in Malayalam: അക്രോട്ട്
walnut in Dutch: Juglans
walnut in Japanese: クルミ
walnut in Norwegian: Valnøtter
walnut in Norwegian Nynorsk: Valnøtt
walnut in Polish: Orzech (roślina)
walnut in Portuguese: Juglans
walnut in Russian: Грецкий орех
walnut in Albanian: Arra
walnut in Finnish: Jalopähkinät
walnut in Swedish: Valnötter
walnut in Thai: วอลนัต
walnut in Turkish: Ceviz
walnut in Ukrainian: Горіх (дерево)
walnut in Chinese: 胡桃
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