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.
lymph cell, lymphocyte - an agranulocytic leukocyte that normally makes up a quarter of the white blood cell count but increases in the presence of infection. vascular system - the vessels and tissue that carry or circulate fluids such as blood or lymph or sap through the body of an animal or plant.