把東西大口吞下去
這一族就是核心畫面本身，沒有轉彎：嘴裡有東西，一大口直接下去。
verb · B1
To swallow food or drink quickly and in large mouthfuls, instead of chewing it properly or drinking it in small amounts.
大口吞下
核心畫面
One big, fast swallow. The throat opens, a whole mouthful goes straight down, and the movement is large enough for other people to see and often to hear. Everything else the word does comes from changing what goes down. Usually it is drink or food. Sometimes it is air, taken in as if you could drink it. And sometimes nothing goes down at all — the throat still moves, and that empty swallow is what fear and nerves look like from the outside. Because the action is visible, gulp is both something you do and something other people read.
「gulp」可以想成喉嚨突然一縮，一大口東西整個滑下去的那個動作。不細嚼，也不小口啜，一次就下去。動作大，所以旁邊的…更多收起
「gulp」可以想成喉嚨突然一縮，一大口東西整個滑下去的那個動作。不細嚼，也不小口啜，一次就下去。動作大，所以旁邊的人常常看得到，甚至聽得到。這個字後面的各種意思，就像只是把「下去的東西」換掉。最常見的是水和食物。也可以是空氣——把空氣當水一樣大口吸進來。還有一種情況是什麼都沒下去：嘴裡是空的，喉嚨卻還是動了一下，那正是緊張和害怕從外面看起來的樣子。所以 gulp 一邊是你做的動作，一邊是別人讀到的訊號。From the word’s history
Wiktionary traces gulp to Middle English gulpen, probably taken from West Flemish or Middle Dutch gulpen; the origin is described as uncertain, and one suggestion there is that the word simply imitates the sound. If that suggestion is right, it sits well with the modern word, which still names a swallow you can hear.
依照維基詞典的說明，gulp 來自中古英語 gulpen，可能是從西佛蘭德語或中古荷蘭語的 gulpen 借來的，來源本身標為不確定。那裡也提到一種可能：這個字本來就是在模仿聲音。如果這個說法成立，它跟今天的用法就對得上——gulp 指的一直是聽得見的那一吞。
Wiktionary 'gulp' etymology section, as supplied in this packet (source_ref kaikki:3f6f69a190036ae4). Origin explicitly marked uncertain there; the imitative account is one suggestion, not a settled fact.
Three branches
大口吸進空氣
核心畫面沒變，只是把下去的東西換成空氣：英文在這裡把空氣當成可以喝的東西，所以連 gulp in、gulp down 都能用在呼吸上。
verb · B2
To breathe air in quickly and in large amounts, as if you were drinking it.
大口吸進（空氣）
什麼都沒吞的那一下
這一族把核心畫面裡的「東西」拿掉，只留下動作：嘴裡是空的，喉嚨還是用力吞了一下。因為那個動作看得到也聽得到，它就從一個生理反應變成別人讀得到的緊張訊號。
verb · B2
To swallow suddenly and hard with nothing in your mouth, because you are surprised, nervous, or afraid.
（緊張地）嚥口水