Akademik

flask with double walls separated by vacuum; used to maintain substances at high or low temperatures

noun, pl ⋯ flasks [count]

Brit : ↑thermos

ˈvacuum flask [vacuum flask] (also flask) (both BrE) (US ˈvacuum bottle) noun

a container like a bottle with double walls with a ↑vacuum between them, used for keeping liquids hot or cold

compare Thermos

See also: ↑flask