The kanji 由 primarily conveys the idea of "origin," "reason," or "cause." It suggests the beginning point or the source from which something originates or stems. It can also imply something "coming from" or "by means of."

・On-yomi (音読み): ユ (yu) ・Kun-yomi (訓読み): よし (yoshi) - This reading is less common and is often seen in the word 由来 (yurai), meaning "origin" or "history."

⚫︎ 理由（riyuu） Translation: reason, cause. ⚫︎ 自由（jiyuu） Translation: freedom. Here, it implies the condition of coming from one's self (one's own reasons, own will). ⚫︎ 経由（keiyu） Translation: via, by way of, through. This suggests the path or route "coming from" or "passing through" a certain point.

The kanji 由 is pictographic in origin. It is believed to represent a container or a vessel, possibly depicting a cup or a vase. The contents inside the vessel suggested the source or origin of something. Over time, the form evolved to its current shape, abstracting the original image but retaining the sense of something emanating or originating from a source.