n. One who maintains the principle of secessionism; specifically, in United States history, one who took part in or sympathized with the attempt of the Southern States, in 1860–65, to withdraw from the Union; an inhabitant of a Southern State who aided or sympathized with the secession movement.Of or pertaining to secession or secessionists.n. Specifically, a member of a body of artists which, in principles and methods, differs from and protests against the accepted traditions of older societies.