The word ‘darkness’ in Russian in antiquity meant ‘10,000’

‘Тьма’ (‘darkness’) is not just the absence of light. Previously, this word had a precise mathematical meaning.
In the ancient numerical system, the word ‘тьма’ (‘tma’; ‘darkness’) meant the number ‘10,000’. It’s taken from the Turkic languages, where the word ‘tumen’ referred to a unit of the Mongol-Tatar army in the 13th-15th centuries, consisting of exactly 10,000 warriors.
Over time, the word came to mean something enormous (‘tma narody’ – ‘a huge crowd of people’) and also acquired the meaning of ‘darkness’, ‘absence of light’.