oak

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of numerous deciduous or evergreen trees or shrubs of the genus Quercus, bearing acorns as fruit.
• noun The hard durable wood of any of these trees or shrubs.
• noun Something made of this wood.
• noun Any of various trees or shrubs having wood or a leaf shape similar to that of certain oaks.
• noun Any of various brown shades resembling the wood of an oak in color.

from The Century Dictionary.

• noun Same as cañon live-oak.
• noun The wall germander, Teucrium Chamædrys.
• noun Gambel's oak, Q. Gambelii.
• noun The Texan oak, Q, Texana.
• noun Same as tarata.
• noun The mountain white oak, Q. Douglasii.
• noun Same as Gambel's oak.
• noun The California white oak, Quercus lobata.
• noun Same as Texan oak.
• noun The water-oak, Q. nigra.
• noun The laurel-oak, Quercus laurifolia.
• noun See Durand's oak.
• noun In Australia, a small malvaceous tree, Lagunaria Patersoni. See whitewood.
• noun A tree or shrub of the genus Quercus, a large and widely dispersed group, chiefly of forest-trees.
• noun One of various other trees or plants in some respects resembling the oak.
• noun The wood of an oak-tree.
• noun One of certain moths: as, the scalloped oak. [British collectors' name.]
• noun The club at cards.
• noun The red oak.
• noun Quercus Emoryi of Texas.
• noun Same as shingle-oak.
• noun The Turkey oak.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Bot.) Any tree or shrub of the genus Quercus. The oaks have alternate leaves, often variously lobed, and staminate flowers in catkins. The fruit is a smooth nut, called an acorn, which is more or less inclosed in a scaly involucre called the cup or cupule. There are now recognized about three hundred species, of which nearly fifty occur in the United States, the rest in Europe, Asia, and the other parts of North America, a very few barely reaching the northern parts of South America and Africa. Many of the oaks form forest trees of grand proportions and live many centuries. The wood is usually hard and tough, and provided with conspicuous medullary rays, forming the silver grain.
• noun The strong wood or timber of the oak.
• noun oak wood colored green by the growth of the mycelium of certain fungi.
• noun a large, smooth, round gall produced on the leaves of the American red oak by a gallfly (Cynips confluens). It is green and pulpy when young.
• noun (Zoöl.) a British geometrid moth (Biston prodromaria) whose larva feeds on the oak.
• noun a gall found on the oak. See 2d Gall.
• noun (Bot.) the mycelium of a fungus which forms leatherlike patches in the fissures of oak wood.
• noun (Zoöl.) See Pruner, the insect.
• noun a kind of gall produced on the oak by the insect Diplolepis lenticularis.
• noun a wartlike gall on the twigs of an oak.
• noun one of the three great annual English horse races (the Derby and St. Leger being the others). It was instituted in 1779 by the Earl of Derby, and so called from his estate.
• noun [Cant, Eng. Univ.] to be “not at home to visitors,” signified by closing the outer (oaken) door of one's rooms.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun countable A tree of the genus Quercus.
• noun uncountable The wood of the oak.
• noun A rich brown colour, like that of oak wood.
• adjective colour of a rich brown colour, like that of oak wood.
• adjective made of oak wood or timber
• adjective consisting of oak trees

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the hard durable wood of any oak; used especially for furniture and flooring
• noun a deciduous tree of the genus Quercus; has acorns and lobed leaves