A castellan; a castellan's wife: with reference to the rank.(noun)
The Century Dictionary (Public Domain)
Use "chastelain" in a sentence
"Marthe was placed under her father's supervision and was ordered to remain in Romorantin unless express permission to depart could be obtained from the "Juge chastelain" of the said locale. 47 Alexis is representative of a developing tendency, at least after the Italian Renaissance, to question antiquated explanations of mysterious phenomena."