'bellicose' originates from Latin, specifically the word 'bellicosus', where 'bellum' meant 'war' and the suffix '-osus' meant 'full of' or 'prone to'.

'bellicose' was borrowed from Latin 'bellicosus' into English (first recorded in the 17th century) largely retaining the sense of 'warlike' or 'pugnacious'.

Initially, it meant 'warlike' or 'full of warlike spirit'; over time it has retained that core meaning but is often used to describe aggressive rhetoric or attitudes as well as literal readiness for war.