Kathreen is a unique and intriguing given name of Irish origin, derived from the ancient Gaelic name Cathriona. It is a feminine form of the name Caitríona, which means 'pure' or 'clear'. Kathreen has been used in various forms throughout history, with notable figures bearing similar names including Catherine of Siena and Catherine the Great.
"Kathreen seems to have been a moderately popular name for newborn girls throughout much of the 20th century, with peaks in usage occurring around the late 1940s and early 1950s. However, it's notable that there were no recorded births with this name after the year 2001."