(av (ǝ) rij): A value that is computed by dividing the sum of a set of terms by the number of terms.

(ka nə pē): A protective covering, such as the uppermost spreading branchy layer of a forest.

(krau̇n): The highest part of the leaves and branches of a tree or shrub.

(i myün si stǝm): The bodily system that protects the body from foreign substances, cells, and tissues by producing the immune response and that includes especially the thymus, spleen, lymph nodes, lymphocytes, and antibodies.

(äp ti kǝl): Of or relating to vision; of, relating to, or using light.

(kwän tǝ tē): A determinate or estimated amount.

(rē flek ti vǝ tē): The capability of reflecting light, images, or sound waves off a surface or material.

(ri lā shǝn ship): The state of being connected through a relation that is known or can be discovered.

(spē sēz or spē shēz): A category of living things that ranks below a genus, is made up of related individuals able to produce fertile offspring, and is identified by a two-part scientific name.

(ǝl trǝ vī lǝt rā dē ā shǝn): Radiation that has a wavelength shorter than wavelengths of visible light (situated beyond the visible spectrum at its violet end) and longer than those of X-rays.