tanka

1. (historical) A coin and unit of currency of varying value, formerly used in parts of India and Central Asia.Examples: "In Uzbek Turan Shah Rukh's tanka remained the standard silver coin and weighed an average of slightly more than 5 g throughout the sixteenth century."; "The last of the gifts was fifteen horses with velvet and jewelled trappings and one hundred thousand tankas in cash."; "A major shift in the usage of silver and billion coinage came about in the second quarter of the fourteenth century when Muḥammad Tughluq, after striking the ṭanka of 169.8 grains in the beginning, replaced it with a coin of lower weight (144 grains) called ‘adli, which was then treated as the standard ṭanka."