A trade term noting a flask, bottle, or the like capable of being kept hot or cold by the device (invented by Sir James Dewar) of surrounding the…

= vacuum flask n. below.

a vessel with a double wall enclosing a vacuum so that liquid in the inner receptacle retains its temperature (cf. Thermos, n.); also transferred in…

Used attributively or absol. to designate a double-walled vessel or flask, usually of glass or copper, having the space between the walls empty of…