Bovril is the trademarked name of a thick, salty beef extract, sold in a distinctive, bulbous jar.
A spoonful of the semi-liquid paste in hot water makes a beef tea. It can also be used as a flavouring for soups and stews, or spread on bread, especially toast.
The name, like many late 19th and early 20th century tradenames comes (partially) from Latin, bos meaning "ox". The vril component of the name comes from Bulwer-Lytton's once-popular 19th century "lost race" novel, The Coming Race, in which a subterranean humanoid race have mental control over, and devastating powers from an energy fluid named "Vril".
