Exoskeleton of cicada attached to Tridax procumbens. An exoskeleton (from Greek Î­Î¾Ï, Ã©xÅ outer and ÏÎºÎµÎ»ÎµÏÏÏ, skeletos skeleton) is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton (endoskeleton) of, for example, a human. In usage, some of the larger kinds of exoskeletons are known as shells.
The term arbitrary here refers to the fact that the symbol that people use is made or chosen without any principle, logic or reason. For example, people in Java do not have a principle or logic to call an animal with long tail, two hands, and two legs and like scratching and playing on trees as kethek.o, to answer Daniel's question: English people do not have any reason why they call the animal that produces meauwww as cat. Again, this is because language is arbitrary: no logical reason is used when choosing a symbol, and no direct relationship between the symbol and the symbolized.
Simple examples. To match a simple pattern with unknown letters just enter it in the âpatternâ box and click on âSearchâ. Example. To solve an anagram type the letters you have into the âall ofâ box and click on âSearchâ.