I just did a basic exercise of trying to define a new word. Let's take Tibetan for example, but the language for this question doesn't matter. I tried starting at the base components, like
ན, to make
ཀན. First of all, there are various definitions by individual authors on thlib.org, so not sure how that factors in. Second, the meaning of the parts often doesn't make the meaning of the whole. In this case ཀ is "primordial" and ན is "sickness" let's say. But you don't get ཀན "primordial sickness" from here, you get Ghana in this case, or in other cases you might end up having two words like "world" and "basket" become "ox" or something like that.
Basically what I'm pointing out is that there doesn't seem to be much relation other than hand-waviness to the parts of a word to the whole. In English and I'm sure in other languages there are things like "bi-cycle", where "bi" is used correctly to mean two, but in many other cases where those higher-level rules don't come into play yet, the roots and stems and such (the "components") don't derive directly from the parts.
So what I'm wondering is what are the rules generally speaking for how words are created across cultures? That is, what is the way to construct new words? At some level is it just arbitrary? Or is there an actual derivation of some sort built in?