thermos flask
- noun
- /ˈθɜrməs flæsk/
- To keep my tea warm during the day, I always carry a thermos flask.
Examples
-
She packed a thermos flask of ice water for the picnic.
-
There's only the thermos flask and the bottle.
-
We debated thermos flasks but went for simplicity.
-
I've got a quart and what's left in the thermos flask.
-
I filled my thermos flask with hot coffee before the long hike.
Synonyms
A container that keeps drinks hot or cold for a long time
A bottle that keeps drinks hot or cold for a long time
A container that keeps drinks hot or cold for a long time
A container with two walls and empty space between them that keeps drinks hot or cold
How Insulating
Surface Forms
Morphology
The meaning is directly and literally built from 'thermos' (a vacuum-sealed container for beverages) plus 'flask' (a container for liquids): together they specify a type of container that keeps liquids hot or cold. This is a straightforward compositional noun phrase common across languages, so a B1 learner who knows both constituents would understand the MWE.
Etymology
Thermos flask gets its name from the Greek word thermos, meaning 'hot', and from the simple bottle idea of a flask with two walls and an empty space between them. That empty space stops heat from moving in or out, so the bottle keeps drinks hot or cold for a long time.