Mucous is a describing word, and almost the only time you will meet it is in the phrase 'mucous membrane' — the soft, wet lining inside your nose, mouth, throat, eyelids and other openings of the body, which stays damp because it produces mucus.

Mucous is a describing word, and almost the only time you will meet it is in the phrase 'mucous membrane' — the soft, wet lining inside your nose, mouth, throat, eyelids and other openings of the body, which stays damp because it produces mucusMucous是一個形容詞，你幾乎只會在'mucous membrane'這個詞裡遇到它——也就是鼻子、嘴巴、喉嚨、眼皮和身體其他開口內側那層柔軟濕潤的黏膜，之所以保持濕潤，是因為它會分泌mucus

Mucus (spelled with -us) is the thick slippery liquid itself: the stuff that runs from your nose when you have a cold, and the stuff that quietly coats and protects your airways all the time. So mucus is the thing, mucous is the word you put in front of another noun.

Mucus (spelled with -us) is the thick slippery liquid itself: the stuff that runs from your nose when you have a cold, and the stuff that quietly coats and protects your airways all the timeMucus（拼法是-us結尾）是那種黏稠滑滑的液體本身：感冒時從鼻子流出來的東西，也是一直悄悄覆蓋、保護你呼吸道的東西 So mucus is the thing, mucous is the word you put in front of another noun所以mucus是那個東西本身，mucous則是你放在另一個名詞前面的字

Both are ordinary medical vocabulary — a doctor or a biology textbook uses them without embarrassment — but in daily conversation English speakers avoid mucus and say 'snot' (childish and informal), 'a runny nose', or 'phlegm' for the thicker kind you cough up from your chest. Knowing the difference matters when you read a medicine box or a doctor's note.

Both are ordinary medical vocabulary — a doctor or a biology textbook uses them without embarrassment — but in daily conversation English speakers avoid mucus and say 'snot' (childish and informal), 'a runny nose', or 'phlegm' for the thicker kind you cough up from your chest這兩個字都是普通的醫學詞彙——醫生或生物課本用起來不會覺得尷尬——但在日常對話裡，英語使用者會避開mucus，改說'snot'（幼稚、口語）、'a runny nose'（流鼻水），或用'phlegm'指從胸腔咳出來比較濃稠的那種 Knowing the difference matters when you read a medicine box or a doctor's note看藥盒或醫生的說明時，知道這個差別很重要