Language is always evolving in some fashion--no language is truly 'static'. This varies by language and culture. One way to observe this is to see the development of dictionaries over time.
This is dependent on what you consider to be the purpose of a dictionary, to me there are two slightly different options:
1) A dictionary is a representation of agreed upon words and their meaning (as in scrabble).
2) A dictionary is a list of how you are likely to encounter a word being used. (as in urban dictionary)
with the latter a dictionary is a tool to help you better understand word/uses that can be unclear, with the former a dictionary provides justification for your choices of wording (the dictionary defines this word so and so, therefore my usage was correct).
In my opinion dictionaries are trying to be 2) but people use them as 1). It is how we get definition of "Literally: not literally, figuratively"; "literally" does not mean "not literally" it is simply used very often like that for emphasis.
1) A dictionary is a representation of agreed upon words and their meaning (as in scrabble).
2) A dictionary is a list of how you are likely to encounter a word being used. (as in urban dictionary)
with the latter a dictionary is a tool to help you better understand word/uses that can be unclear, with the former a dictionary provides justification for your choices of wording (the dictionary defines this word so and so, therefore my usage was correct).
In my opinion dictionaries are trying to be 2) but people use them as 1). It is how we get definition of "Literally: not literally, figuratively"; "literally" does not mean "not literally" it is simply used very often like that for emphasis.