vacuum flask

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A bottle, flask or similar vessel having a vacuum between its inner and outer silvered walls; designed to maintain the temperature of its contents
• noun chemistry A Dewar vessel is the scientific version, and is most often used to store liquified gases.
• noun chemistry A type of glass flask used in a laboratory similar to an Erlenmeyer flask, but with a side spout used for connection to an aspirator. Also known as a Büchner flask.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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