Rein is of German origin, derived from the element 'ragin', which means "powerful" or "warrior". It is often associated with the Old Norse word 'rín', meaning "advice" or "wise counsel". The name Rein gained popularity during the Middle Ages in Germany and has since been used in various other cultures.
"Rein experienced a significant increase in popularity from 2021 to 2023, with 13 and 15 births respectively, following a steady growth since 2014."