Select Page

Archives: Dictionary


/lēf/ Noun, pl. leaves (Botany) 1. An organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants. Typically a leaf is a thin, flattened organ borne above ground and specialized for photosynthesis, but many types of leaves are adapted in ways almost unrecognisable in those terms: some are not flat (for example many succulent leaves and conifers), some are not above ground (such as bulb scales), and some are without major photosynthetic function (consider for example cataphylls, spines, and cotyledons). ( 2. A coloured, usually green, expansion growing from the side of a stem or rootstock, in which the sap for the use of the plant is elaborated under the influence of light; one of the parts of a plant which collectively constitute its foliage. Such leaves usually consist of a blade, or lamina, supported upon a leafstalk or petiole, which, continued through the blade as the midrib, gives off woody ribs and veins that support the cellular texture. The petiole has usually some sort of an appendage on each side of its base, which is called the stipule. The green parenchyma of the leaf is covered with a thin epiderm pierced with closable microscopic openings, known as stomata. ( 3. The usually green and flat organ that represents...

Read More


/leg/ Noun, pl. legs 1. A weight bearing and locomotive structure, usually having a columnar shape. During locomotion, legs function as “extensible struts”. The combination of movements at all joints can be modeled as a single, linear element capable of changing length and rotating about an omnidirectional “hip” joint. ( 2. An anatomical animal structure used for locomotion. The distal end is often modified to distribute force (such as a foot). Most animals have an even number of legs. ( 3. The lower limb of a human being or animal that extends from the groin to the ankle. ( 4. A limb or member of an animal used for supporting the body, and in running, climbing, and swimming; especially, that part of the limb between the knee and foot. ( 5. The portion of the lower appendage of a human that extends from the knee to the ankle. ( 6. That which resembles a leg in form or use; especially, any long and slender support on which any object rests; as, the leg of a table; the leg of pair of compasses or dividers. ( 7. The part of any article of clothing which covers the leg; as, the leg of a stocking or of a pair of trousers. ( 8. A bow, especially. In the phrase to make a leg; probably from drawing the leg backward in bowing....

Read More


Noun, pl. lemnisci (Zoology) 1. One of two oval bodies hanging from the interior walls of the body in the Acanthocephala. ( (Anatomy) 1. A part of the brain, such as the medial lemniscus or lateral lemniscus. ( 2. A bundle of sensory nerve fibers going to the thalamus. ( 3. A bundle of secondary sensory fibers within the brain stem which terminates in specific relay nuclei of the diencephalon. ( Word origin: From Late Latin lemniscus “a pendent ribbon.” from Greek lemniskos “woolen ribbon,” perhaps originally or literally “of Lemnos,” island in the...

Read More


/lenz/ Noun, pl. lenses (Anatomy) 1. A transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. ( 2. The transparent crystalline structure in the eye. ( (Geometory) 1. A convex shape bounded by two circular arcs, joined at their endpoints, the corresponding concave shape being a lune. ( (Biology) 1. A genus of the legume family; its bean. ( 2. Genus of small erect or climbing herbs with pinnate leaves and small inconspicuous white flowers and small flattened pods: lentils. ( (Other definitions) 1. An object, usually made of glass, that focuses or defocuses the light that passes through it. ( 2. A device which focuses or defocuses electron beams. ( 3. A piece of glass or other transparent substance with curved sides for concentrating or dispersing light rays, used singly (as in a magnifying glass) or with other lenses (as in a telescope). (Google Dictionary) 4. The light-gathering device of a camera, typically containing a group of compound lenses. (Google Dictionary) 5. An object or device that focuses or otherwise modifies the direction of movement...

Read More


Adjective 1. Shaped like a lens. ( 2. Convex on both sides; shaped like a lentil. ( Syn: lenticular, biconvex, convexo-convex Word origin: From Latin lens = “lentil,” and forma,...

Read More
  • 1
  • 2

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how