Asteroids are celestial rocky bodies that orbit the sun. It was Sir William Herschel who first coined the term âasteroidâ (Greek for star-like) in 1802. He thought that Ceres and Pallas, discovered in 1801 by Giuseppe Piazzi and Heinrich Olbers respectively, were too small and were remnants of a destroyed planet.
blood cell. n. Any of the cells contained in blood; an erythrocyte or leukocyte; a blood corpuscle. blood cell. n. (Physiology) any of the cells that circulate in the blood. See erythrocyte, leucocyte.
whiteâ² bloodâ² cell`. any of various nearly colorless cells of the immune system that circulate mainly in the blood and lymph, comprising the B cells, T cells, macrophages, monocytes, and granulocytes. Also called leukocyte, whiteâ² bloodâ² cor`puscle, whiteâ² cell`. (wÄ«t).