Mean
When I say I really mean it, I am trying to add emphasis to my intention. I can also say that what I really mean is … That is supposed to clarify something where my intent seems to be misunderstood. It could also be that my intent is in doubt. You don’t believe I mean it and will tear up this document (usually with an ‘unless you… ‘ included)… so I kind of raise the threat level.
 
In mathematics, the mean is the simple average of a group of measurements. This can work well when talking about the weight of a bunch of potatoes. Although there is a factual part to expressing the mean of an attribute of a group of people, be careful. To say someone is above or below the mean can be innocuous until we substitute average for mean. Now some are above or, oh oh, below average. We can be touchy
 
If I am mean toward you I am being nasty, provoking, relentless even, not nice. To be mean is a defense reaction. I am not feeling top of my game, maybe angry at something, not even you, grouchy, threatened, deflated and in order to push you away I can act in a mean manner. Mean feels to be a member of the evil family. What do you think?
 
GMT stands for Greenwich Mean Time. That is the time related to the annual average (mean) of when the sun crosses the Greenwich meridian in England, at noon. The mean, average, is used because the earth is not a perfect sphere but rather an approximation of an oblate spheroid (you wanted to know that didn’t you) which is quite lumpy. From that reference point world time is calculated
 
In the meantime… What does that have to do with any kind of average or being nasty or underlining emphasis? It is not a time when things are hurtful but simply ‘while we wait’. I don’t have the means, whoops, that word again, to understand how all these meanings (again) were decided upon, even less than by whom. Where do word meanings come from? Is this man’s search for meaning?