able, aimless, amorphous, bald, bare, capricious, casual, desultory, disarticulated, disclosed, discontinuous, disjunct, disordered, dispersed, disproportionate, enigmatic, erratic, exposed, fitful, formless, frivolous, gratuitous, haphazard, hit-or-miss, immethodical, incalculable, inchoate, incognizable, incoherent, indiscriminate, irregular, meaningless, misshapen, mysterious, naked, nonsymmetrical, nonsystematic, nonuniform, open, open as day, open to all, orderless, overt, planless, promiscuous, puzzling, random, revealed, sealed, senseless, shapeless, spasmodic, sporadic, straggling, straggly, strange, systemless, unapparent, unapprehended, unarranged, unascertained, unbeknown, uncharted, undirected, undisclosed, undiscoverable, undiscovered, undivulged, unexplained, unexplored, unexposed, unfamiliar, unfathomed, ungraded, unheard, unheard-of, unidentified, uninvestigated, unjoined, unknowable, unknown, unmethodical, unordered, unorganized, unperceived, unplumbed, unrevealed, unsorted, unsuspected, unsymmetrical, unsystematic, untouched, ununiform, vague, virgin, wandering

For further exploring for "unclassified" in Webster Dictionary Online