The English word 'Hinduism' is a relatively modern term used to describe the diverse religious traditions originating in the Indian subcontinent. Historical evidence indicates that the term was first notably used and popularized in the English language by the scholar and social reformer Raja Ram Mohan Roy.
Raja Ram Mohan Roy, a key figure in the 19th-century Bengal Renaissance, is credited with being among the first prominent scholars to employ the term 'Hinduism' in English. He used this term to differentiate the religious aspects from the geographical and cultural identity of 'Hindustan' (India).
While the roots of the practices referred to as Hinduism are ancient, the specific English nomenclature 'Hinduism' gained currency largely through the efforts of Roy and subsequent scholars seeking to categorize and understand these traditions within a Western academic framework.
Therefore, Raja Ram Mohan Roy is identified as the scholar who first significantly used the English word 'Hinduism'.