沒有袖子的上半截衣服
兩個意思都是「上半截、沒有袖子」，差別只在材質和地區。
noun · A2
In American English, a light shirt with no sleeves and wide shoulder straps, worn in hot weather, for exercise, or under other clothes.
背心（無袖上衣）
核心畫面
Take a shirt and cut the sleeves away. What is left is the top part only — shoulders, chest, back, and two wide straps. That is the picture the clothing senses share: the upper piece, with nothing on the arms. What that piece is made of then splits the two countries: thin cotton for summer in America, knitted wool for winter in Britain.
可以想成拿一件上衣，把兩隻袖子剪掉。剩下的就是「上半截」：肩膀、前胸、後背，加上兩條比較寬的肩帶。衣服這邊的兩個意思…更多收起
可以想成拿一件上衣，把兩隻袖子剪掉。剩下的就是「上半截」：肩膀、前胸、後背，加上兩條比較寬的肩帶。衣服這邊的兩個意思，共用的就是這個畫面——只有上半身，手臂空著。接下來材質一分，兩個國家就分開了：美式是夏天的薄棉，英式是冬天的毛線。所以看到這個字，先看季節和搭配，畫面就對得上了。From the word’s history
Wiktionary records that a tank top was the upper part of a tank suit — the one-piece swimming costume worn by women when swimming pools were called swimming tanks. The shape of that upper part is what the name kept.
Wiktionary 記的是：以前游泳池叫 swimming tank，女生穿的連身泳衣叫 tank suit，而 tank top 本來指那件泳衣的上半截。留下來的不是泳衣，而是那個形狀——沒有袖子的上半身。
Wiktionary entry for “tank top” (local kaikki extract, source_ref kaikki:3f6f69a190036ae4:579925725)
Two branches
船上的「櫃的頂」
這一組跟衣服沒有關係，是另外一條路：tank 在這裡是真的水櫃油櫃，top 是它的頂蓋。放在同一頁只是因為拼法一樣。
noun · C1
On a ship, the flat surface that closes the top of the tanks in the bottom of the hull — usually the lowest level you can stand on inside the ship.
（船）艙底櫃頂板
原始詞典資料2 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
tank topnoun
- 1
An item of casual clothing: a top with no sleeves.
- The service makes available, during limited weekend hours, a handful of the company's items – cargo shorts, tank tops, and the like – to the Hamptons house guest who discovers that he can't make it to Monday without purchasing one of those weird madras patchwork blazers.
- 2
The top of a ship's bilge tank, usually the lowest horizontal surface on board.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。