'bravo' originates from Italian, specifically the word 'bravo', where the root meant 'courageous', 'wild', or 'savage'.

'bravo' passed from Italian into Spanish and other Romance languages and was borrowed into English (17th century). The theatrical practice of shouting 'Bravo!' to praise a performer helped fix the exclamation sense in English.

Initially, it meant 'a bold or savage person' or 'a hired ruffian'; over time the sense shifted (especially in theatre) to the current primary meaning of 'an exclamation of approval' or 'praise'.