Definitions for "Antirequisite"
Students may not enroll in a course that lists, as an antirequisite, one that they are also taking or which they have already passed.
a specific course or level of attainment which, if already successfully completed, does not permit registration for credit in another desired course, or which may not be taken for credit concurrently with another course
is a course which cannot be taken for credit before, after, or at the same time as the course with which it is listed.