自己翻過去的人
這一支離字面最近：翻滾的人就叫 tumbler。其他家族都可以看成從這個畫面往外走。
noun · C1
A performer who turns the body over in the air or on the ground — rolls, flips and somersaults — usually as part of a show or a team.
翻筋斗的人；特技表演者
核心畫面
One way to hold the whole word: a tumbler is whatever tumbles. The source records the word as tumble plus -er, the one that does it. So the picture underneath every use is something going over instead of staying upright. A body turning in the air. A glass that will not stand still. Small parts dropping into place inside a lock. A drum rolling stones over and over until they shine. The learner-dictionary order puts the drinking glass first because that is the sense people meet most, but the person who turns over is the one closest to the plain meaning of the parts.
tumbler 可以想成「會翻滾的那一個」。來源把它拆成 tumble（翻倒、翻滾）加上 -er（做這件事的人或東西…更多收起
tumbler 可以想成「會翻滾的那一個」。來源把它拆成 tumble（翻倒、翻滾）加上 -er（做這件事的人或東西）。所以底下的畫面都一樣：不是好好立著，而是翻過去。有人在空中翻一圈。有杯子底不平，放不穩就倒。有鎖裡的小零件掉進定位。也有滾筒把石頭一圈一圈翻到發亮。學習型字典把玻璃杯排在最前面，因為那是最常遇到的意思；不過離字面最近的，是那個翻筋斗的人。這條線只是幫你把幾個意思串起來的想法，不必當成每個用法的證據。From the word’s history
The packet's Wiktionary entry records the word as tumble + -er, that is, the one that tumbles. Each family below is a different answer to the question of what is doing the tumbling: a person, the glass itself, the parts inside a lock, or the things loaded into a machine.
來源把這個字記成 tumble 加 -er，也就是「翻滾的那一個」。下面每一個家族其實是在回答同一個問題：到底是誰在翻。是人自己翻，是杯子自己倒，是鎖裡的零件落下去，還是被放進機器裡的東西在滾。
Wiktionary entry for tumbler, supplied in this packet (source_ref kaikki:3f6f69a190036ae4:525954149:41738): From tumble + -er.
Four branches
站不穩的杯子
這一支不是人在翻，而是杯子自己會倒。從「會翻的東西」走到「那種杯子」，再走到「一杯的量」。
noun · B2
A drinking glass with a flat bottom and straight sides, with no thin stem under it and no handle on the side. It is the plain everyday glass you drink water, juice or milk from.
平底玻璃杯
落進定位的小零件
翻滾在這裡縮小成「落下去」。零件不是翻一圈，而是掉進它該在的高度，門閂才鬆開。
noun · C1
A small moving part inside a lock — a pin, lever, disc or wheel — that has to be pushed to exactly the right position before the bolt can move. The cuts along a key lift all of them at once, and then the lock turns.
鎖裡的制栓（彈子）
讓別的東西翻滾的機器
前面幾支是自己翻，這一支是「讓別人翻」。-er 指的變成造成翻滾的那台機器或那個服務。
noun · C1
A machine with a chamber that turns round and round, so the things put inside it roll against grit and against each other. Rough stones, beads or small metal parts go in dull and come out smooth and shiny.
滾筒研磨機