Designating a qualification or course of study at a higher level than the elementary, esp. designating a degree which is (usually) superior to a…

Of or relating to the period after graduating; designating a course or institution for people undertaking a higher qualification after completing…

Prior or preliminary to professional training.

Of, designating, or relating to education subsequent to primary school; (of a pupil): receiving such education.

Of or relating to postgraduate students or courses; = postgraduate, adj.