thermos: meaning, definition, pronunciation and examples
B1Everyday, informal
Quick answer
What does “thermos” mean?
A brand name that has become generic for a double-walled container used to keep liquids hot or cold.
Audio
Pronunciation
Definition
Meaning and Definition
A brand name that has become generic for a double-walled container used to keep liquids hot or cold.
Any similar vacuum-insulated flask used to store drinks at a desired temperature. Can sometimes be used metaphorically for something that maintains a stable internal state despite external changes.
Dialectal Variation
British vs American Usage
Differences
In British English, 'flask' is a very common alternative, especially 'vacuum flask'. 'Thermos' is understood but may be perceived as more of a brand name. In American English, 'thermos' is the dominant generic term.
Connotations
UK: May carry a slight commercial connotation. US: Fully generic, everyday term.
Frequency
Higher frequency in American English; 'flask' is more common in UK English for the same object.
Grammar
How to Use “thermos” in a Sentence
[Verb] a thermos: fill, pack, carry, bring, open[Adjective] thermos: hot, cold, full, empty, insulatedVocabulary
Collocations
Examples
Examples of “thermos” in a Sentence
verb
British English
- The brand advises not to thermos carbonated drinks. (rare, non-standard)
American English
- (No standard verb use)
adverb
British English
- (No standard adverb use)
American English
- (No standard adverb use)
adjective
British English
- She brought a thermos flask on the hike.
American English
- He poured coffee from his thermos bottle.
Usage
Meaning in Context
Business
Rare, except in retail or manufacturing contexts ('thermos sales', 'thermos production line').
Academic
Rare, except in physics or engineering discussions of insulation principles.
Everyday
Very common, especially in contexts of travel, picnics, work, and outdoor activities.
Technical
Used in product design and materials science ('thermos technology', 'thermos seal').
Vocabulary
Synonyms of “thermos”
Strong
Neutral
Weak
Vocabulary
Antonyms of “thermos”
Watch out
Common Mistakes When Using “thermos”
- Using uncountable ('some thermos'). It's a count noun. Spelling: 'thermos' (lowercase when generic). Confusing with 'thermostat'.
FAQ
Frequently Asked Questions
It originated as a trademark (from Greek 'thermē' meaning heat), but in common usage, especially in American English, it has become a generic term for any vacuum flask. The company still owns the trademark.
In UK English, 'flask' often means 'vacuum flask' (a thermos). In US English, 'flask' more commonly refers to a flat container for spirits (a hip flask). A 'thermos' in the US specifically denotes an insulated container for hot/cold drinks.
In British English: /ˈθɜː.mɒs/ (THER-moss). In American English: /ˈθɝː.məs/ (THER-muss). The first syllable rhymes with 'her'.
Both 'thermoses' and 'thermos' are used. 'Thermoses' is more common and standard. Using 'thermos' as a plural (e.g., 'two thermos') is informal.
A brand name that has become generic for a double-walled container used to keep liquids hot or cold.
Thermos is usually everyday, informal in register.
Phrases
Idioms & Phrases
- “None directly. Can be used in metaphorical constructions: 'He's a human thermos, never shows his emotions.'”
Learning
Memory Aids
Mnemonic
Think: 'THERMal flOSk' shortened to THERMOS. It keeps things THERMally stable.
Conceptual Metaphor
CONTAINER FOR TEMPERATURE (The thermos is a portable, stable micro-environment).
Practice
Quiz
In which sentence is the word 'thermos' used correctly?