Learn English – Difference between “rule” and “law” in scientific context

When this word is used by programmers, it is a synonym for "authoritative," "standard," or "official." That's meaning number 3 in the definition you quote.

It implies that there is one best, most official, most standard way to represent the string object and this is it.

For example sometimes things can be represented using a relative link or an absolute link. Relative might be something like ../foo.txt meaning "The file foo.txt in the folder above this one" while absolute is something like \\www.example.com\fileserver\share\foo.txt which can only refer to one file on the Internet. One might say that the latter name is canonical.

I generally think of medium as being of some sort of the middle of a static range, (statistically it is defined as the value halfway between the mininum and maximum values), such as being of medium height, while intermediate is about the middle of a process such as the intermediate level music examinations are what you would have to pass through to get from beginner level to advanced level.

The other important point is that a given case may have several intermediate levels or states but will only have one medium point.

The other difference is that a specific sample might not contain any of the medium value but a range of states must pass through the intermediate value as they progress.

To use them in a physics sense I would say:

• in a set of samples for stress testing a medium sheer point of 10 N was found but
• in all samples 7 N was found to be an intermediate point between the elastic limit and the sheer point.

In your coupling context I would say that possibly single a system can be strongly coupled or weakly coupled and has one or more intermediate levels of coupling but if each of a set of systems can only have one level of coupling then the middle level between the highest and lowest will be medium coupling.