牆與防守：把地方圍起來
最字面的一支，殼是真的牆，裡面是真的地方。其他家族都是從這裡把畫面搬到別的東西上。
verb · B2
To build walls, towers, fences or other strong structures around a place, so that it is hard for an enemy to get in.
設防／築防禦工事
核心畫面
Picture putting a hard shell around something so that whatever comes at it from outside cannot get through. A town gets a stone wall; the town itself has not changed, but it is now much harder to reach. Every other use of fortify keeps that shape and only changes what is inside the shell: a belief, a person's standing, a tired body, a statement, even a bowl of cereal. Wherever you meet the word, ask two questions: what is being protected, and what is the wall made of?
可以想成幫某個東西套上一層硬殼，讓外面來的東西不容易穿過去。一座城鎮築起石牆之後，城鎮本身沒有變，但要靠近它變難了很…更多收起
可以想成幫某個東西套上一層硬殼，讓外面來的東西不容易穿過去。一座城鎮築起石牆之後，城鎮本身沒有變，但要靠近它變難了很多。fortify 其他的用法都沿用這個形狀，只是換掉殼裡面的東西：一個信念、一個人的地位、一副疲累的身體、一段說法，甚至一碗麥片。所以每次遇到這個字，可以問自己兩件事——被保護的是什麼，牆又是用什麼做的。From the word’s history
The source traces fortify through Late Middle English fortifien and Old French fortifier to Late Latin fortificare, to strengthen or fortify, built on Latin fortis, powerful or strong. So the literal build is strong plus make, and the walls are simply where English put that idea first.
來源把 fortify 一路追到晚期中古英語 fortifien、古法文 fortifier，再到晚期拉丁文 fortificāre（使變強），底下是拉丁文 fortis（強、有力）。所以它字面上的組成就是「強」加「使變成」。城牆只是英文最早把這個概念放進去的地方，不是這個字本來的限制，這也說明了為什麼它後來可以蓋到心情、說法和食物上。
Wiktionary (kaikki extract), fortify verb etymology: From Late Middle English fortifien, from Old French fortifier, from Late Latin fortificare (to strengthen, fortify), from Latin fortis (powerful, strong).
Four branches
立場與說法：不容易被推倒
殼搬到看不見的東西外面。被守的不是城，而是你握著的信念、地位，或你講出口的那段話；牆則換成事件與證據。
verb · C1
To make a feeling, a belief, or someone's position stronger, so that it is harder to shake or to argue away.
鞏固／使更堅定
人變強：先補好再上路
殼套到人身上。要面對的難關就是外面的天氣，熱湯、熱茶和一句鼓勵就是那層牆。
verb · C1
To make yourself or someone else feel stronger in body or mind, usually with food, a hot drink, or a few encouraging words, before something hard.
補充體力／打起精神
食物變強：把營養加進去
這一支的殼比較不像牆，比較像「補進去的那一層」。被加強的是食物能給身體的東西，加的是有名字的營養素。
verb · B2
To add vitamins or minerals to a food or drink so that it gives people more of what their body needs.
強化營養／添加營養素