便宜
べんぎ · bengi · JLPT N1 · noun
convenience
🏨 便 = convenient + 宜 = suitable, so 便宜 = convenience or accommodation
Both characters are about fitting the situation: 便 means convenient and 宜 means appropriate. In Chinese the same word more often means cheap, so check the context.
便 — person 亻 + change 更
A semantic compound: 亻(person) beside 更 (to change/replace). The original sense was a person making things easier or more convenient by adjusting them. From 'convenient' it extended to 'then/thereupon' (biàn) and to bodily 'discharge' (as in 大便).