Thermos most commonly refers to: Thermos L.L.C., a brand of domestic vacuum flasks A vacuum flask, also commonly referred to as a "thermos" Thermos may refer to: Thermos (Aetolia), an ancient Greek city, the capital city of the Aetolian League A thermos bomb, the AR-4 anti-personnel bomb used during World War II A No. 73 grenade, an anti-tank hand grenade of World War II Thermos, a 1990 album by Bailter Space See also Thermus (disambiguation)