An animal shell, the arduous, rigid outer covering of an beast like the mollusk or a turtle. A tough outer layer of a select few plant fruiting bodies like nuts. The nature and severity of user interface in computer software, often an operating system shell, such as the Unix shell command line interpreter in the Unix operating system or the DOS Shell in MS-DOS. Understand shell (computer science). An electron shell (energy level), consisting of the total of electrons in an orbital around an atomic nucleus A short title (& Brand) of the Royal Dutch Shell Energy multinational. The projectile with explosive charge, shot from the gun; typically husks come big than bullets and shot from either big guns. View shell (projectile). Inside physics, see On shell and off shell The structural form, ordinarily processed of concrete, that principally derives its nature and severity by virtue of its shape. A term is from either a primary usage in the context of nature and severity. E.g., a plate of an egg though very thinly is hard to break because of its shape. An extended, narrow, rowed watercraft. Look at racing shell. The sorting algorithm fancied by Donald L. Shell. Watch shell sort.