• 理由りゆう — reason
• 由来ゆらい — origin
• 自由じゆう — freedom
• 経由けいゆ — via, through
• 由緒ゆいしょ — lineage, history
• 由よし — cause, reason (archaic form)

This kanji originally showed the shape of a wine gourd and came to mean “reason” or “cause.” It forms the base for many abstract words related to logic, explanation, and freedom.