Tamil is the oldest living language. This means that the Tamil language spoken by the people is the same as was the Tamil spoken two or three thousand years ago. This is true only partially as Tamil people cannot understand the literature of sangam period (1 BC to 1 AD) without some assistance by way of meaning for words which are no longer in usage. However, fortunately, many of the words which are not in use in the present Tamil is in use in sister languages like Malayalam, Kannada and Telugu(particularly Malayalam).. For example, words- nouns like Wellam(water), sevi(ear), oon(meal) vurakkam(sleep) and verbs like (kazhinge), iiy(give), perugu(increase), nagu(smile) –are in current use in these languages. Media should play a major role in popularizing and using these and also the words which are not in use in any of the Dravidian languages.
Government should also encourage usage of old literary Tamil words which are not currently used in Tamil language by instituting awards for those writers and media who bring such words in current usage.
Of course, the people should stop mixing foreign words in their Tamil conversation.
Tamil will be truly the oldest living language only when the words do not disappear and are not replaced with new words with the passage of time. There is however no bar for adding new words.