A euphemism is a mild or polite way of referring to something that is unpleasant, embarrassing, or socially unacceptable, such as death or activities usually done in private.
>... they found Saul and his sons <u>fallen</u> on Mount Gilboa. (1 Chronicles 10:8 ULB)
This means that Saul and his sons "were dead". It is a euphemism because the important thing was not that Saul and his sons had fallen but that they were dead. Sometimes people do not like to speak directly about death because it is unpleasant.
Different languages use different euphemisms. If the target language does not use the same euphemism as in the source language, readers may not understand what it means and they may think that the writer means only what the words literally say.
The original hearers would have understood that Saul went into the cave to use it as a toilet, but the writer wanted to avoid offending or distracting them, so **he did not say specifically** what Saul did or what he left in the cave.