Also an adjective, having a long shadow or inhabiting the polar regions. The first definition is the literal (that is, etymological) one, the second the practical (that is, metaphoric). This seems to have been swiped from Greek, but it could have been coined from Greek roots macros, long + skia, shadow. Compare ascian, one without a shadow, or via metaphoric extension, one who inhabits the torrid regions near the equator -- which just doesn't have the same oomph.
Our latest tribulation is a hoard of macroscian Vikings.