'Guru' originates from Sanskrit, specifically the word 'गुरु (guru),' where 'गु (gu)' meant 'darkness' and 'रु (ru)' meant 'dispeller.'

'गुरु (guru)' was adopted into Hindi and other Indian languages, and eventually became the modern English word 'guru.'

Initially, it meant 'spiritual teacher,' but over time it evolved into its current meaning of 'expert or leader in a field.'