Similar word to untended:

abandoned, beat-up, below par, broken-down, crumbling, debilitated, decrepit, derelict, deserted, desolate, dilapidated, dingy, dog-eared, down-at-the-heel, drained, enervated, exhausted, fatigued, forsaken, frowzy, in a bad way, neglected, old, out of condition, peaked, ramshackle, ratty, rickety, seedy, tacky, tattered, tired, tumble-down, uncared-for, under the weather, unhealthy, untended, used up, weak, weary, worn-out