What is the reason of defining multiple meanings of a single word? [closed]

If you are designing a language from scratch, and the purpose of that language is communication of information reliably and efficiently whether in a chaotic or entirely controlled environment then, yes, you totally want strings of base symbols to have a one-to-one map to semantics.

This is an informal way of describing the situation of coding theory, bit transfer over a noisy channel a highly studied engineering discipline.

However, people aren't machines. Or at least not in the engineered way. So things like 'reason' or 'purpose' or 'user experience' are only whispery myths that are only vaguely appear mirage-like to human, natural language.

Which is to say that human language is not designed at all. It is not logical, the choices made in outward form are arbitrary (and frankly capricious).

Usually context will differentiate:

"Don't listen to that old man, he is just a story teller, repeating exaggerated legends."

vs

"That man made the Kessel run in twelve parsecs, he's a true legend."

Context says one is about a story and the other about a person. Why bother designing an entirely different string for a similar concept when it's really easy to differentiate? If you check your dictionary, most words have more than one meaning (usually nearby). In fact I think it is rare that a word has a single meaning. The only place where that happens is in math and science (and even then words often have controversy with multiple 'stipulated' definitions).

Look man, brains aren't computers. There's no code running on that mass of curdled cheese inside your skull. There's no database of words and ther definitions and there's no algorithm that inserts definitions for the words and then compiles to brain-bytecode. Yeah, there totally is electricity or really electrical potential, or really changes in electrical potential from differences in ion pumping between inside and outside over the length of neurons. After that, the information processing model of neurology is a very rough model.

Many of the features of language look like they are consciously designed by a very well educated and thoughtful designer but that is just a mirage. It is all unconscious. OK, 'telephone' was made up by that one guy.

None of this is particular to English. All languages have semantic drift, metaphorical usages that lead to distinct situations labeled with the same word.