on the spur of the moment(r = adv.all) suddenly - on impulse; without premeditation; "he decided to go to Chicago on the spur of the moment"; "he made up his mind suddenly"

N  impulse, sudden thought, impromptu, improvisation, inspiration, flash, spurt, improvisatore, creature of impulse, extemporaneous, impulsive, indeliberate, snap, improvised, improvisate, improvisatory, unpremeditated, unmeditated, improvise, unprompted, unguided, natural, unguarded, spontaneous, instinctive, extempore, extemporaneously, offhand, impromptu, a limproviste, improviso, on the spur of the moment, on the spur of the occasion, impulse, impulsion, impetus, momentum, push, pulsion, thrust, shove, jog, jolt, brunt, booming, boost, throw, explosion, propulsion, percussion, concussion, collision, occursion, clash, encounter, cannon, carambole, appulse, shock, crash, bump, impact, elan, charge, beating, blow, dint, stroke, knock, tap, rap, slap, smack, pat, dab, fillip, slam, bang, hit, whack, thwack, cuff, squash, dowse, swap, whap, punch, thump, pelt, kick, punce, calcitration, ruade, arietation, cut, thrust, lunge, yerk, carom, carrom, clip, jab, plug, sidewinder, sidewipe, sideswipe, hammer, sledge hammer, mall, maul, mallet, flail, ram, rammer, battering ram, monkey, pile-driving engine, punch, bat, cant hook, cudgel, ax, dynamics, seismometer, accelerometer, earthquake detector, impelling, impulsive, impellent, booming, dynamic, dynamical, impelled, a hit, a very palpable hit.

N  instantaneity, instantaneousness, immediacy, suddenness, abruptness, moment, instant, second, minute, twinkling, trice, flash, breath, crack, jiffy, coup, burst, flash of lightning, stroke of time, epoch, time, time of day, time of night, hour, minute, very minute, very time, very hour, present time, right time, true time, exact correct time, instantaneous, momentary, sudden, immediate, instant, abrupt, discontinuous, precipitous, precipitant, precipitate, subitaneous, hasty, quick as thought, quick as lightning, quick as a flash, rapid as electricity, speedy, quick, fast, fleet, swift, lively, blitz, rapid (velocity), instantaneously, in no time, in less than no time, presto, subito, instanter, suddenly, at a stroke, like a shot, in a moment, in the blink of an eye, in the twinkling of an eye, in a trice, in one's tracks, right away, toute a l'heure, at one jump, in the same breath, per saltum, uno saltu, at once, all at once, plump, slap, at one fell swoop, at the same instant, immediately, extempore, on the moment, on the spot, on the spur of the moment, no sooner said than done, just then, slap-dash, touch and go, no sooner said than done.

N  the present, the present time, the present day, the present moment, the present juncture, the present occasion, the times, the existing time, the time being, today, these days, nowadays, our times, modern times, the twentieth century, nonce, crisis, epoch, day, hour, age, time of life, present, actual, instant, current, existing, extant, that is, present-day, up-to-date, up-to-the-moment, at this time, at this moment, at the present time, now, at present, at hand, at this time of day, today, nowadays, already, even now, but now, just now, on the present occasion, for the time being, for the nonce, pro hac vice, on the nail, on the spot, on the spur of the moment, until now, to this day, to the present day, the present hour alone is man's.

N  earliness, morning, punctuality, promptitude, haste, suddenness, prematurity, precocity, precipitation, anticipation, a stitch in time, early, prime, forward, prompt, summary, premature, precipitate, precocious, prevenient, anticipatory, rath, sudden, unexpected, near, near at hand, immediate, early, soon, anon, betimes, rath, eft, eftsoons, ere long, before long, shortly, beforehand, prematurely, precipitately, too soon, before its time, before one's time, in anticipation, unexpectedly, suddenly, before one can say 'Jack Robinson', at short notice, extempore, on the spur of the moment, on the spur of the occasion, at once, on the spot, on the instant, at sight, offhand, out of hand, a' vue d'oeil, straight, straightway, straightforth, forthwith, incontinently, summarily, immediately, briefly, shortly, quickly, speedily, apace, before the ink is dry, almost immediately, presently at the first opportunity, in no long time, by and by, in a while, directly, no sooner said than done, immediately, if not sooner, tout vient a temps pour qui sait attendre.

N  timeliness, occasion, opportunity, opening, room, event (eventuality), suitable season, proper season, suitable time, proper time, high time, opportuneness, tempestivity, crisis, turn, juncture, conjuncture, crisis, turning point, given time, nick of time, golden opportunity, well timed opportunity, fine opportunity, favorable opportunity, opening, clear stage, fair field, mollia tempora, fata Morgana, spare time, opportune, timely, well-timed, timeful, seasonable, providential, lucky, fortunate, happy, favorable, propitious, auspicious, critical, suitable, obiter dicta, opportunely, in proper course, in due course, in proper season, in due season, in proper time, in due time, for the nonce, in the nick of time, in the fullness of time, all in good time, just in time, at the eleventh hour, now or never, by the way, by the by, en passant, a propos, pro re nata, pro hac vice, par parenthese, parenthetically, by way of parenthesis, incidentally, while speaking of, while on the subject, extempore, on the spur of the moment, on the spur of the occasion, on the spot, carpe diem occasionem cognosce, one's hour is come, the time is up, that reminds me, now that you mention it, come to think of it, bien perdu bien connu, e sempre l'ora, ex quovis ligno non fit Mercurius, nosce tempus, nunc aut nunquam.

dipole moment, electric dipole moment, first moment, for the moment, in a moment, magnetic dipole moment, magnetic moment, moment, moment of a couple, moment of a magnet, moment of inertia, moment of truth, present moment, psychological moment, second moment, senior moment, spur, spur blight, spur gear, spur track, spur wheel