ad infinitum, again and again, at a stretch, at attention, bolt upright, ceaselessly, connectedly, constantly, continually, continuously, cumulatively, cyclically, endlessly, endways, endwise, erectly, incessantly, interminably, monotonously, on a stretch, on and on, perennially, repetitively, right on end
, round the clock, together, unbrokenly, unceasingly, unintermittently, uninterruptedly, unrelievedly, up, up on end
, upright, uprightly, upstandingly, without a break, without cease, without stopping
verticality, erectness, perpendicularity, right angle, normal, azimuth circle, wall, precipice, cliff, elevation, erection, square, plumb line, plummet, vertical, upright, erect, perpendicular, plumb, normal, straight, bolt, upright, rampant, standing up, rectangular, orthogonal, vertically, up, on end
, up on end
, right on end
, a plomb, endwise, one one's legs, at right angles.