THESAURUS
Impetus
acceleration, activity, animation, ardor, brio, briskness, catalyst, clout, compulsion, drive, driving force, elan, encouragement, energy, enthusiasm, getaway, glow, goad, gusto, impellent, impelling force, impetuosity, impulse, impulsion, incentive, incitation, incitement, inspiration, irresistible force, joie de vivre, life, liveliness, lustiness, mettle, moment, momentum, motivation, motive power, perkiness, pertness, pickup, power, propulsion, push, quickening, robustness, speedup, spirit, spiritedness, spur, step-up, stimulant, stimulation, stimulus, thrust, vivacity, warmth, zest, zestfulness
ROGET THESAURUS
Impetus
Impulse
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.