non-tenured       
adjective (also nontenured) uk/ˌnɒnˈten.jəd/ us/ˌnɑːnˈten.jɚd/
 (大学教师)非终身制的
used to refer to a teacher in a college or university who does not have tenure (= the right to remain permanently in a job)
  Approximately 20% of the staff are non-tenured.  大约有20%的教职工不是终身制的。 
 Many non-tenured teachers had their contracts terminated.
 - More examples
 - As long as you are non-tenured, you will always feel less secure in your job.
 - He was offered the entry-level, non-tenured position of assistant librarian.
 - The department has eight tenured and four nontenured professors as well as a handful of part-time teachers.