One way to hold this word: a surface made of small flat pieces that lie over each other, like tiles on a roof. Run your hand across it and you feel the edges. Every use of scaly comes back to that surface — first on a fish, then on anything else that breaks into overlapping pieces.
可以想成一個畫面：一個表面被一小片一小片又薄又平的東西蓋滿，一片壓著一片，像屋頂上的瓦。用手摸過去，摸得到那些邊。scaly 的各種用法都回到這個表面。最早是魚身上的鱗，後來凡是裂成一片片、疊成一層層的東西，也都借用了這個畫面。
From the word’s history
By surface analysis, scale plus the ending -y, which means covered with or full of; recorded in Middle English as scali.
從構詞上看，scaly 就是 scale（鱗片）加上 -y（帶有…的、滿是…的），中古英語寫作 scali。所以這個字從一開始講的就是「身上帶著鱗片」，後來的用法都是從這個字面畫面延伸出去的。
Wiktionary entry for scaly (kaikki:3f6f69a190036ae4:662291764): From Middle English scali, skaly. By surface analysis, scale + -y.
登入就可以看每一支怎麼連回核心畫面。