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 好朋友 · 碎魚誘餌
chum
noun, verb核心畫面
You can picture a chum as someone you shared a small space with — a room, a desk, a boat — for long enough that being together mattered more than choosing each other. That is why the word sounds easy rather than deep, and why it also once meant the person you shared a room with.
chum 可以想成「一起待在同一個小空間裡的人」：同寢室、同張課桌、同一條船。重點不是你多欣賞對方，而是你們待在一起…更多收起
chum 可以想成「一起待在同一個小空間裡的人」：同寢室、同張課桌、同一條船。重點不是你多欣賞對方，而是你們待在一起夠久了。所以這個字聽起來輕鬆、不用客氣，也因此它舊時候還可以直接指「室友」。From the word’s history
One account of the word derives it from chambermate, shortened to cham and then chum; another connects it to comrade. Both routes are uncertain, and both point at the same picture: people sharing one space.
一種說法是 chum 來自 chambermate（同房的人），先縮成 cham 再變 chum；另一種說法把它連到 comrade。資料明說來源不確定，但兩條線都指向同一個畫面：共用一個空間的人。
Wiktionary etymology 1 as supplied in this evidence packet (kaikki:3f6f69a190036ae4): "1675-85; of uncertain origin, possibly from cham, shortening of chambermate, or from comrade."
A second word, same spelling
chum
noun, verb核心畫面
Picture a bucket of chopped fish going over the side of a boat. The oil and blood spread out into a long invisible trail, and fish follow the smell in from far away. Everything in this branch is about that trail: the stuff you pour, and the pouring.
可以想成船邊倒下去的一桶碎魚：油和血在水裡拉出一條看不見的味道帶，遠處的魚順著味道一路靠過來。這一支的每個意思都圍著…更多收起
可以想成船邊倒下去的一桶碎魚：油和血在水裡拉出一條看不見的味道帶，遠處的魚順著味道一路靠過來。這一支的每個意思都圍著那條味道帶——倒下去的東西，和倒的動作。From the word’s history
The sources treat this as a different word that happens to share the spelling. It is recorded as originally American English from the 1850s, perhaps from Powhatan.
資料把這個 chum 列為另一條完全不同的來源，只是拼法剛好一樣。它大約 1850 年代起於美式英語，可能來自 Powhatan 語。
Wiktionary etymology 2 as supplied in this evidence packet (kaikki:3f6f69a190036ae4): "Originally American English, from the 1850s. Perhaps from Powhatan."