The spelling of the name "Cristen" is derived from the more common "Christian". The "t" replaces the "h" but the sound is the same, /kɹɪs.tʃən/. The first syllable is stressed, /ˈkɹɪs/, and is pronounced with a short "i" sound. The final syllable, /tən/, is pronounced with a schwa sound. The spelling variation is likely due to regional or cultural differences, but the name is still recognized and accepted as a variation of the original spelling.
The word "Cristen" is derived from the Old English word "Crístendōm" which means "Christianity" or "Christendom". It is a compound word formed by combining "Críst" (Christ) and "endōm" (state, condition, or quality). Over time, "Crístendōm" became "Cristendom" and later was anglicized to "Cristen". The term originally referred to the collective body of Christians or the followers of Christ.