Millionaire Mode

What does the author mean by the expression 'fixing the meaning of the words we use'?

Directions: Read the following passage to answer the given question.

If our thoughts are to be clear and we are to succeed in communicating them to other people, we must have some method of fixing the meaning of the words we use. When we use a word whose meaning is not certain, we may well be asked to define it. There is a useful traditional device for doing this by indicating the class to which it belongs, and also the particular property which distinguishes it from all other members of the same class. Thus, we may define a whale as a marine animal that spouts. “Marine animal” in this definition indicates the general class to which the whale belongs, and spouts indicate the particular property that distinguishes whales from other such marine animals as fish, seals, jellyfish and lobsters. In the same way, we can define an even number as a finite integer divisible by two or democracy as a system of government in which the people themselves rule.

There are other ways of course of indicating the meaning of words. We may for example, find it hard to make a suitable definition of the word ‘animal’, so we say that an animal is such a thing as a rabbit, dog, fish or goat. Similarly, we may say that religion is such a system as Christianity, Islam, Judaism and Buddhism. This way of indicating the meaning of a term by enumerating examples of what it includes is obviously of limited utility. If we indicated our use of the word animal as above, our hearers might, for example be doubtful whether a sea anemone or a slug was to be included in the class of animals. It is however, a useful way of supplementing a definition, if the definition itself is definite without being easily understandable. Failure of an attempt at definition to serve its purpose may result from giving it a distinguishing mark which either does not belong to all the things the definition intends to include, or does belong to some members of the same general class which the definition intends to exclude.