Is a teacher legally allowed to call a student a judgemental name because of the clothes the student is wearing?

According to
most educators' codes of ethics, name-calling of students is considered unprofessional at least,
and a terminable offense at the worst, meaning it can get a teacher fired. However, legally
speaking, a teacher can "label" a student in certain ways that fall outside the realm
of religion, race, lifestyle, or socioeconomic status. As an example, if a student comes into
class with their pants too low and the teacher calls the child a "plumber," referring
to the pants' exposure of the buttocks, then that label is legally defensible, although
inappropriate. However, if the teacher in question labels a female student a "slut"
for wearing clothing that exposes too much anatomy, that incident then falls into the realm of
sexual harassment or even slander. This question also hinges upon state laws governing educator
standards. You may wish to check your local laws regarding this matter.