thermos UK /ˈθɜː.mɒs/US /ˈθɝ.məs/ noun2 •A bottle, flask or similar vessel having a vacuum between its inner and outer silvered walls; designed to maintain the temperature of its contents •(historical) A unit of measure whose identification remains very unclear.1 saton (seʾah) = 1/3 ephah (see above for correction) = 2/3 bath / mina by weight = 50 shekels / ¼ shekel = 4 thermoi / shekel = 16 thermoi and one weight (?) — 2005 formsthermoi · thermoi · thermoses