Rannie is of Irish origin, derived from the ancient Gaelic word 'Rannach', meaning 'little seal'. It was often used as a nickname for someone who was agile and swift, likened to the sleek movements of a seal in water.
The name Rannie experienced varied popularity over the years, with peaks in certain decades and lower usage in others. Between 1914 to 1967, there were a total of 205 babies named Rannie. The highest number of births in any single year was 14 in 1927, while some years saw as few as 5 births. After the late 1960s, it seems that the name Rannie became less common, with no further data provided.