I am having a hard time understanding a word this is used to show me one of the key features of language.

Question

can anyone give an example or explain this to me because i am real confused I was at an understanding that Arbitrary was somethig said that was not true to describe something. Please Help here is what we was given.

Arbitrary: The relationship between the elements in the language and their meaning is arbitrary. There is no special reason the word chair must have the referent that it does. It would be perfectly acceptable for the utterance table to have the referent that chair now does. The word big doesn’t have to be in some sense “bigger” than the word minuscule.
Arbitrariness is a key feature of symbols. A sound stands for a meaning,
but which sound stands for which meaning is arbitrary.

Answer 1

from http://www.thesaurus.com

Main Entry: arbitrary
Part of Speech: adjective
Definition: whimsical, chance
Synonyms: approximate, capricious, discretionary, erratic, fanciful, frivolous, inconsistent, injudicious, irrational, irresponsible, offhand, optional, random, subjective, supercilious, superficial, unaccountable, unreasonable, unscientific, wayward, willful

Answer 2

The easiest way to think of the word "arbitrary" I think, is "open to question". If something can be open to question(not set) , then the answer would be "arbitrary"..