Pure
Carynn is a modern American spelling variant of Karen, which is the Danish form of Katherine. It ultimately derives from the Greek word 'katharos', meaning pure, and has been adapted into various phonetic spellings in the late 20th century.
Less common today
Carynn isn't in the latest US Top 1000. It last peaked at #9,855 in 1992.
US births per 5-year period, 1990βpresent (SSA data).