- 1黏度、黏滯性。台灣理化課本就講「黏度」「黏滯係數」；機油包裝上的等級講的就是這個。形容詞是 viscous（黏稠的）。
Viscosity is how thick a liquid is and how much it resists flowing. Water has low viscosity — it runs off your hand at once. Honey has high viscosity — it takes its time. That is the whole idea, and it is a measurable quantity, not just an impression: engineers give it a number, which is why you see grades like 10W-40 printed on engine oil.
Because it is a measurement word, it takes the language of measurement: viscosity increases, decreases, is high or low. Temperature is the usual thing that changes it — heat oil and its viscosity drops, cool it and the oil . That single fact is behind most sentences you will meet with this word, from cooking to car maintenance to volcanoes.
It is usually uncountable: the viscosity of the fluid. You will sometimes see "viscosities" when several different liquids are being compared, and that is fine.
Outside science, people occasionally use it as a metaphor for slowness or stickiness in things that are not liquid at all — the viscosity of a bureaucracy. That is a writer's flourish, not standard use, and everyone hears the joke.
The adjective is : a liquid is one with high viscosity.
From the word’s history
From Middle French viscosité, from Medieval Latin viscositas; viscous + -ity.
源自中世紀拉丁文 viscositas；即 viscous（黏稠）加 -ity。
組成Comes through Old and Middle French from Medieval Latin viscositas. You can also read it as English viscous + -ity, the ending that turns an adjective into the name of a quality — the way pure becomes purity. Behind it all sits Latin viscum, mistletoe or birdlime, the original sticky stuff.
原始詞典資料3 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
viscositynoun/vɪsˈkɑsɪti/
- 1
The state of being viscous.
- Near-synonym: thickness
- 2
natural-sciencesphysical-sciencesphysicsA quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.
- The microcannon was seen moving at about a micron per second, it was about 15 microns long, and the high speed photograph was done in water (density of 1 kg/L, viscosity of about 0.001 pascal seconds).
- Aquafaba was recovered from 10 commercial canned chickpea products and correlations among aquafaba composition, density, viscosity and foaming properties were investigated. Proton NMR was used to characterize aquafaba composition before and after ultrafiltration through membranes with different molecular weight cut offs (MWCOs of 3, 10, or 50 kDa).
- 3
human-sciencespsychologysciencesA tendency to prolong interpersonal encounters.
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。