'anguineous' originates from Latin, specifically the word 'anguineus,' where 'anguis' meant 'snake' and the suffix '-eus' meant 'pertaining to' or 'made of.'

'anguineus' passed through Late and Medieval Latin; English adopted forms like 'anguine' and 'anguineous,' which eventually stabilized as the modern English adjective 'anguineous.'

Initially, it meant 'of a snake; snake-like,' and this sense has remained in modern usage, chiefly in learned or literary contexts.