用土地換忠誠的人
這是那筆交換最原始的樣子，主角是一個人。
noun · C2
In the Middle Ages in Europe, a man who was given land to live on by a lord, and who promised in return to serve that lord and to fight for him.
封臣
核心畫面
You can think of a vassal as someone to hand over his freedom and standing up holding a piece of land. Both halves matter: he gets something real to live on, and he gives up the right to choose. Every later use of the word keeps that trade — protection and resources coming down, loyalty and obedience going up.
vassal 可以想成一個人跪下去交出自由，站起來手上多了一塊可以活下去的地。兩邊都要看：他確實拿到了實質的東西，但…更多收起
vassal 可以想成一個人跪下去交出自由，站起來手上多了一塊可以活下去的地。兩邊都要看：他確實拿到了實質的東西，但他也交出了自己決定的權利。這個字後來的每一種用法，底下都還是這筆交換——上面給資源和保護，下面回以忠誠和聽話。From the word’s history
Wiktionary traces it through Old French vassal and Medieval Latin vassallus (manservant, retainer) to Latin vassus (servant), from Gaulish *wassos (young man, squire) — the picture throughout is of a young man attached to someone else's household.
來源資料把這個字一路追到古法文 vassal、中世紀拉丁文 vassallus（僕從、隨從）、拉丁文 vassus（僕人），再到高盧語 *wassos（年輕人、侍從）。從頭到尾的畫面都是「跟在別人身邊做事的年輕人」。
Wiktionary (kaikki) entry for 'vassal' supplied in the evidence packet (source_ref kaikki:3f6f69a190036ae4:672308107:23388)
Two branches
被別人決定的國家
同一筆交換，主角從一個人換成一個國家：名字還在，決定權不在。
noun · C2
A country that is not really independent, because a stronger country decides what it does.
附庸國