The mathematical term for "mean" is "mean".The popular, or colloquial term for "mean" is "average".
It means to work out the answer of a given mathematical problem.
Mean is the mathematical term for average.
The sx is for supercross.
Convention is not a mathematical term: it means what is generally done or an accepted way of doing something.
It means an explanation
it means to be wrong
Sx means symptoms
Inspiration is not a mathematical term. It, therefore, means what it does in normal usage.