1. When I use a term it means only what I want it to mean (mean by it) "neither more nor less".
(The Humpty-Dumpty theory).
2. Terms have essential meanings so that it is possible for everyone to use a term wrongly. (For instance, the essential meaning of "philosopher" is "lover of wisdom" so even if everyone thinks that A. J. Ayer was a philosopher, but if Ayer was not a lover of wisdom, then Ayer was not a philosopher. (The Platonic theory of meaning)
3. "Words are a wise man's counters, but they are the money of fools" Thomas Hobbes.
You are talking about definitions rather than meanings, and to an essetial degree, if we do not define our words to serve our purpose we will be defined to serve the purpose of those who define our words...
Meaning is a quality apart from words, and it is all well and good to seek some objective meaning in words, but it is our meaning, the meaning of our lives that make words meaningful... In ther words, they are are but signs without significance, or worse, having only subjective meaning, and it is for tyranny and exploitation and injustice and slavery that words are so bastardized... We have no common language... We communicate with friends, and neighbors in one tongue and with strangers and enemies in another... What the rich say, and what government says is seldom believed, even when they say the truth... What the people say, they say to themselves because government is issolated and living in fear, giving the rabble what they think will quiet their murmers...You see, that the proper use of language is communication, and communication is truth, and for that, the definition of any particular word is inessential, because truth and communication are not a single event, but a way of life, and a life goal; is not one way, but is a form of relationship... So very often words can be given a temporary meaning without problem, but when government, and the wealthy debase the whole ability of the people to communicate in order to destroy the ability of the people to organize resistence, then they have made certain their own bloody ends... They do not govern, but deny government... They rule as every group or dictator, by a monopoly on intelligence, with propaganda instread of truth, with subtle twists of meaning, and with inuendo... You don't have to worry about most people unless they are lip syncing the blather of the powerful... Most people know things are not as they should be, and seek consolation as much as communication... I seek both, and understanding as well... I know when I am being lied to...I can see when a whole country is living a lie for there are many examples in history to compare to ours...