把氣裝進去，鼓成一團
這一組是把那口氣留在裡面。東西因此變大、變圓、變厚，外形本身就是名字的由來。
noun · B2
A tropical fish that can fill its own body with air or water until it swells up into a round ball. It does this when something frightens it, and many kinds carry poison inside them.
河豚
核心畫面
You can think of a puffer as the thing that puffs. A puff is one short breath of air. Some puffers send a little cloud of air out; others fill up with air until they go round and fat. Hold that one breath of air in mind and the fish, the medicine device and the winter coat all sit in the same picture.
puffer 可以想成「跟一口氣有關的那個東西」。puff 就是短短的一口氣。有的 puffer 是把那口氣噴出去，…更多收起
puffer 可以想成「跟一口氣有關的那個東西」。puff 就是短短的一口氣。有的 puffer 是把那口氣噴出去，像按一下就噴出藥的吸入器；有的 puffer 是把那口氣裝進自己身體裡，鼓成圓圓的一團，像河豚，也像塞滿羽絨的厚外套。先記住「一口氣」這個畫面，三個意思就不會各走各的。From the word’s history
Wiktionary analyses the word as puff + -er, that is, the one that puffs.
來源資料把這個字拆成 puff（吹一口氣）加上 -er（做這件事的人或東西），所以字面就是「會吹氣的那個」，正好對上現在的每一個用法。
Wiktionary entry for puffer, etymology_text in this packet: From puff + -er.
Two branches
把氣噴出來
這一組是把那口氣往外送。動作方向跟上一組相反，但講的還是同一口氣。
noun · B2
A small piece of equipment that holds medicine. You put it in your mouth, press it, and breathe the medicine in, so that you can breathe more easily.
吸入器