Word Study
on end
THESAURUS
on end
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 stoppingROGET THESAURUS
on end
Verticality
N 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.For further exploring for "on end" in Webster Dictionary Online