身體長期很弱
這一組就是病房本身，字面的用法，其他意思都是從這裡借畫面出去的。
adjective · B2
Weak and unhealthy, and ill a lot of the time. It is used about a person or an animal, and also about a plant that grows thin, pale and badly.
體弱多病的
核心畫面
Think of the look and feel of a sick room: a thin body that never quite gets strong, a face with no colour in it, and air that is too sweet and too still. Sickly takes that whole room and lends it to other things. The word never says a thing IS ill. It says the thing has the look, the colour, the smell or the weakness of illness — and that you would rather not be near it. That dislike is always part of the word, which is why almost nothing described as sickly is being praised.
「sickly」可以想成一間病房裡的感覺：一個怎麼養都養不壯的身體、一張沒有血色的臉、還有那股太甜又不流動的空氣。這…更多收起
「sickly」可以想成一間病房裡的感覺：一個怎麼養都養不壯的身體、一張沒有血色的臉、還有那股太甜又不流動的空氣。這個字把整間病房借給別的東西用。它其實從來不是在說「這個東西生病了」。它說的是：這個東西帶著生病的樣子、顏色、氣味或虛弱感。而且說的人不想靠近。這種嫌惡幾乎一定在裡面，所以被叫做 sickly 的東西，很少是在被誇獎。From the word’s history
Middle English sekely, from sick + -ly. The ending stretches a one-time illness into a lasting look, which is why the word describes a condition rather than an event.
來自中古英文 sekely，就是 sick（生病的）加上 -ly。可以想成 -ly 把「生病」這件一次性的事，拉長成一種持續的樣子。這條線索正好對上今天的用法：sickly 說的是狀態，不是某一次的事件。
Wiktionary entry for sickly (etymology 1), etymology_text supplied in packet (source_ref kaikki:3f6f69a190036ae4:1156275529:37595)
Three branches
看起來發虛、沒力氣
只借走病房裡「臉色」那一塊：白、薄、撐不起來。從臉挪到顏色、光，再挪到表情。
adjective · B2
Used about a colour or a light: pale, weak and unpleasant to look at, the way an unhealthy face looks.
（顏色、光線）慘白發虛的
甜膩到反胃
這一支借的不是臉色，是「想吐」那個身體反應：味道濃到把噁心感勾起來。
adjective · B2
Used about a smell or a taste: so heavy and sweet that it turns your stomach. It is also used about music, films or writing that are sweet in the same too-much way. This use is especially common in British English.
甜膩到反胃的