A follower of Christ
Kierstynn is a modern American creative spelling of Kirsten, which is the Scandinavian form of Christina. It ultimately derives from the Latin name Christianus, meaning 'follower of Christ'. This specific spelling variation adds a contemporary flair to a traditional name.
Less common today
Kierstynn isn't in the latest US Top 1000. It last peaked at #9,534 in 1995.
US births per 5-year period, 1990βpresent (SSA data).