Bovril is the trademarked name of a thick, salty meat extract, developed in the 1870s by John Lawson Johnston. It is sold in a distinctive, bulbous jar.
Bovril can be made into a drink by diluting with hot water, or less commonly, with milk. It can be used as a flavouring for soups, stews or porridge, or spread on bread, especially on toast in a similar fashion to Marmite and Vegemite.
(via Nag on the Lake)