看得見的上面那一層
最直接的用法：底座之上、看得見的那一塊實體結構。
noun · B2
The part of a ship, building or bridge that is built on top of its main base, and that you can see rising above it.
上層結構
核心畫面
Think of two layers, one on top of the other. The lower layer was there first and carries the weight; the upper layer was added later and depends on it. Super- means above and structure means a built thing, so superstructure is simply the layer on top. On a ship it is the cabins above the deck, in a building it is everything above the foundation, and in writing about society it is the laws and ideas standing on the economy. The word is about position, not about size or importance.
superstructure 可以想成上下兩層的畫面。下面那層先在，而且負責撐；上面那層是後來架上去的，靠下面撐著。…更多收起
superstructure 可以想成上下兩層的畫面。下面那層先在，而且負責撐；上面那層是後來架上去的，靠下面撐著。super- 是「在上面」，structure 是「結構」，合起來就是上面那一層。在船上是甲板以上的艙房，在建築上是地基以上看得到的部分，在談社會的文字裡就是架在經濟之上的法律和觀念。要注意它講的是位置，不是大小，也不是重要性——上面那層不見得比較重要，只是比較晚出現、比較顯眼。From the word’s history
Wiktionary gives super- + structure, with super- from Latin super, meaning above. The literal reading - the thing built on top - is still exactly what the word does in both uses.
字典把這個字拆成 super- ＋ structure，而 super- 來自拉丁文 super（在…之上）。字面就是「蓋在上面的結構」，今天的兩個用法都還照著這個字面走，一個蓋在船和樓上，一個蓋在經濟上。
Wiktionary entry for superstructure, packet etymology_text: "From super- + structure" (super- from Latin super).
Two branches
架在基礎之上的制度與觀念
同一張上下兩層的圖搬到社會上：下面是經濟活動，上面是長出來的制度。
noun · C1
A political, social or legal system that has grown on top of a simpler or more basic one, such as the laws, ideas and institutions that stand on a country's economy.
上層建築