When a speaker is trying to express something that does not have the right representation is his language or even environment, they use something resembling an analogy or a metaphor. For example, tribes that had never seen a railroad before may call it an "iron horse" because they don't even have a concept of a railroad. Is there a better word for this figure of speech or the process itself?
Edit: another example. Imagine that people from some primitive culture witnessed a landing of a spacecraft and saw astronauts coming out of it. To describe what they saw they would have to say something like "A shining boat descended from the sky and gods in shiny furs came out of it" because they have no notion of space travel or clothes made of anything but fur. Maybe "primitive metaphor" is the right way call this? Or is there a better word?