fluid: meaning, definition, pronunciation and examples
B2Formal, technical, and everyday
Quick answer
What does “fluid” mean?
A substance that flows and yields to pressure.
Audio
Pronunciation
Definition
Meaning and Definition
A substance that flows and yields to pressure; not rigid or solid.
Capable of flowing; smooth and continuous in movement or change; not fixed or stable.
Dialectal Variation
British vs American Usage
Differences
Minimal semantic difference. 'Fluid ounce' measurements differ between UK (20 ml) and US (29.6 ml).
Connotations
Similar positive connotations (grace, adaptability) and neutral technical uses.
Frequency
Comparably frequent in both varieties, with slight preference in UK English for 'liquid' in some everyday contexts.
Grammar
How to Use “fluid” in a Sentence
noun + of + fluid (a drop of fluid)verb + fluid (drain the fluid)fluid + noun (fluid intelligence)be + fluid + in + noun (be fluid in one's approach)Vocabulary
Collocations
Examples
Examples of “fluid” in a Sentence
verb
British English
- The design team will fluid the transition between the old and new systems.
American English
- The manager decided to fluid the project timeline to accommodate changes.
Usage
Meaning in Context
Business
Describes adaptable business models or cash flow (e.g., 'fluid capital').
Academic
Used in physics, biology, medicine, and social sciences (e.g., 'fluid intelligence', 'gender fluid').
Everyday
Refers to drinks, car maintenance, or flexible plans (e.g., 'drink plenty of fluids').
Technical
Precise term in engineering and medicine (e.g., 'hydraulic fluid', 'cerebrospinal fluid').
Watch out
Common Mistakes When Using “fluid”
- Using 'fluid' as a synonym for 'enough water' (e.g., 'I need to drink more fluid' sounds odd; use 'fluids' or 'liquid').
- Confusing 'fluid' (adaptable) with 'floating' (on surface).
FAQ
Frequently Asked Questions
All liquids are fluids, but not all fluids are liquids (gases are also fluids). 'Liquid' is more specific to state, while 'fluid' emphasises flow properties and is more common in technical/scientific contexts.
It can be both. Uncountable: 'There's fluid on the lung.' Countable (often plural): 'Drink plenty of fluids.'
In psychology, it refers to the capacity to think logically and solve novel problems, independent of acquired knowledge. It is contrasted with 'crystallised intelligence' (knowledge from experience).
Yes, it can describe someone adaptable or whose identity (e.g., gender) is not fixed (e.g., 'gender-fluid'). It can also describe graceful movement (e.g., 'a fluid dancer').
A substance that flows and yields to pressure.
Fluid is usually formal, technical, and everyday in register.
Fluid: in British English it is pronounced /ˈfluːɪd/, and in American English it is pronounced /ˈfluːɪd/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Go with the fluid (less common variant of 'go with the flow')”
- “Fluid situation”
Learning
Memory Aids
Mnemonic
FLU-id: Imagine the FLU makes your nose run with a flowing, liquid substance.
Conceptual Metaphor
CHANGE IS FLUID MOTION (e.g., 'The plans are still fluid.'); INTELLIGENCE IS A FLUID (e.g., 'fluid reasoning').
Practice
Quiz
In which context is 'fluid' used metaphorically?