Follower of Christ
Kierston is an Americanized phonetic variant of the Scandinavian name Kirsten, which is a cognate of Christina. It ultimately derives from the Greek name Christos, referring to a follower of the Christian faith. While less common than its counterparts, it offers a distinct spelling that emphasizes the 'Kier' sound.
Less common today
Kierston isn't in the latest US Top 1000. It last peaked at #3,001 in 1990.
US births per 5-year period, 1990βpresent (SSA data).