thermos flask vs thermos bottle

thermos flask and thermos bottle both are nouns.

Word	Noun	Adjective	Verb	Adverb
thermos flask	Yes	No	No	No
thermos bottle	Yes	No	No	No

As nouns, thermos flask and thermos bottle are synonyms defined as:

thermos flask and thermos bottle: vacuum flask that preserves temperature of hot or cold drinks

Other synonyms of thermos flask include thermos.

thermos flask (noun)	thermos bottle (noun)
vacuum flask that preserves temperature of hot or cold drinks	vacuum flask that preserves temperature of hot or cold drinks