adjective, bur·ri·er, bur·ri·est. full of or covered with burs; burlike. adjective, bur·ri·er, bur·ri·est.characterized by or spoken with a burr. adjective -rier or -riest full of or covered in burs resembling burs; prickly adj.mid-15c., "full of burs;" see bur + -y (2).