這個拼法底下其實是2個不同的字，意思沒有關係， 只是長得一樣。下面分開列出來。跳到 fatty (containing fat) · fatty (insult: fat person)
fatty
a, n核心畫面
One way to picture it: fat itself, turned into a describing word — you are looking at something and saying "there is a lot of fat sitting in this." A slice of pork with wide white bands running through it, oil floating on top of the soup, a piece of skin that shines and leaves your fingers slippery.
把「脂肪」這個東西直接拿來當形容詞用——你看著一樣東西，說的是「這裡頭有很多油脂」。一塊豬肉切開，白色的油花一條一條…更多收起
把「脂肪」這個東西直接拿來當形容詞用——你看著一樣東西，說的是「這裡頭有很多油脂」。一塊豬肉切開，白色的油花一條一條夾在紅肉裡；湯放涼了，表面浮起一層油；咬下去嘴唇亮亮的、手指摸過會滑。fat 是那個東西本身，加上 -y 之後，就變成「帶著那個東西的樣子」。From the word’s history
fatty is simply fat + the adjective ending -y, inherited from Middle English fatty and matching Dutch vettig and German fettig — so the word never travelled anywhere: it is fat wearing an adjective's coat.
fatty 就是 fat 加上形容詞字尾 -y，直接來自中古英語 fatty，跟荷蘭語 vettig、德語 fettig 是同一套造字方式。所以這個字沒有繞過任何遠路：它從頭到尾就是 fat 披上形容詞的外衣，意思也就一直貼著「有脂肪在裡面」。
Wiktionary, "fatty" (Etymology 1, adjective): Middle English fatty, equivalent to fat + -y; cognate with Dutch vettig, German fettig.
A second word, same spelling
fatty
n核心畫面
A different word that happens to look the same: here -y is the small, familiar ending you find in doggy or daddy, stuck onto fat to make a name for a person. The picture is a playground shout — someone points at a heavy person and calls them by that one feature, as if that were their whole name.
這是另一個剛好長得一樣的字。這裡的 -y 不是「帶有…的」，而是像 doggy、daddy 裡那個親暱／小稱的字尾，…更多收起
這是另一個剛好長得一樣的字。這裡的 -y 不是「帶有…的」，而是像 doggy、daddy 裡那個親暱／小稱的字尾，黏在 fat 後面，把一個形容詞變成叫人的稱呼。核心畫面可以想成：操場上有人指著一個體型胖的人喊出來——把那個人身上一個特徵拿來當成他整個名字。也正因為是「拿一個特徵替代整個人」，這個字帶著明顯的攻擊性。From the word’s history
The noun is fat + the diminutive suffix -y (the same ending as in doggy), which turns a quality into a name for a person carrying it.
名詞的 fatty 是 fat 加上小稱字尾 -y（跟 doggy 的 -y 同一個），作用是把一個特質變成「有這個特質的那個人」的叫法。這種造字方式本身是親暱的，但用在體型上就變成嘲弄——形式上像綽號，實際上是攻擊。
Wiktionary, "fatty" (Etymology 2, noun): from fat + -y (diminutive suffix); Old English -iġ > Middle English -y.
原始詞典資料8 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。
fattyadj詞源 1/ˈfæt.i/
- 1
Containing, composed of, or consisting of fat.
- fatty tissues
- fatty meats
- 2
Containing, composed of, or consisting of fat.
- fatty liver
- fatty pancreas
- 3
Like fat; greasy.
- 4
Of or related to fat.
- fatty acid
- fatty alcohol
- 5
slangLiterally or figuratively large.
- Be careful of the taxi drivers out there though, I've heard they sell you drugs, drop you off at your hotel and then dob you in to the Thai Police to get a fatty reward!
- Instead of going my normal route (ordering the book through the store, checking it out in person, and then ordering it online so I could get a fatty discount) I impulsively bought the book.
fattynoun詞源 2
- 1
derogatoryslangAn obese person.
- It's hardly surprising, when it has to support that enormous gut! Lose some weight, fatty!
- 2
slangA large marijuana cigar; a blunt.
- We went to Plaster Creek, smoked a fattie, and emerged doing somersaults and cartwheels and laughing.
- 3
A type of game played with marbles.
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。