• jig, purifier, screen, sifter
• filamentary, filamentous, stringy
• to bolt, to fan, to jig, to riddle, to screen, to van, to ventilate, to winnow
• cipher-stencil, ciphering grid, ciphering square, grate, grid, grill, grille, lattice
• bolting, jigging, screening, winnowing
• underflow, unders, undersize
• underflow, unders, undersize
• through coal, through-and-through coal
• overflow, overs, oversize