'get-go' originates from American English, specifically the phrase 'get going,' where 'get' meant 'to start' and 'going' meant 'in motion.'

'get going' transformed into the colloquial term 'get-go' in American English, emphasizing the start of an action or event.

Initially, it meant 'to start moving,' but over time it evolved into its current meaning of 'the very beginning.'