稀到會流的東西
核心畫面最直接的樣子：東西本身太稀，所以站不住、留不住形狀。
adjective · B1
Food that is runny is thinner and more liquid than it usually is, or than you wanted it to be, so it flows instead of holding its shape.
稀的；會流動的
核心畫面
Picture something that will not stay where you put it. You tip the spoon and it slides off; you leave it on the plate and it spreads out to the edge. English has one verb for what a liquid does when it behaves like this — it runs — and runny is simply the adjective for anything doing it. The word carries a quiet expectation with it: this thing should have been thicker, or should have stayed inside.
runny 可以想成「留不住、會自己跑掉」的樣子。湯匙一斜它就滑下去，放在盤子上它會攤開到邊緣。英文把液體這種動作叫…更多收起
runny 可以想成「留不住、會自己跑掉」的樣子。湯匙一斜它就滑下去，放在盤子上它會攤開到邊緣。英文把液體這種動作叫 run，runny 就是形容正在這樣做的東西。這個字背後通常藏著一個期待：它本來應該再稠一點，或者本來應該待在裡面不要出來。From the word’s history
From run plus the ending -y, so literally having the quality of running — of flowing.
來自 run 加上 -y。run 除了人在跑，也是英文形容液體流動的動詞，所以 runny 字面就是「帶有流動性質的」。兩個意思都直接從這裡長出來。
Wiktionary entry for runny (packet evidence, source_ref kaikki:3f6f69a190036ae4:1049455218:8672): From run + -y.
Two branches
一直流出來的鼻子和眼睛
同樣是「留不住」，只是位置換到身體上：該待在裡面的液體一直跑出來。
adjective · A2
If your nose or your eyes are runny, liquid keeps coming out of them, usually because you have a cold, an allergy, or cold wind in your face.
流鼻水的；流眼淚的