Impetus

• POS: Noun
• HYPHEN: im=pe=tus

CIDE DICTIONARY

Impetus, n. [L., fr. impetere to rush upon, attack; pref. im- in + petere to fall upon, seek. See Petition.].

•  A property possessed by a moving body in virtue of its weight and its motion; the force with which any body is driven or impelled; momentum.  [1913 Webster]

  " Momentum is the technical term, impetus its popular equivalent, yet differing from it as applied commonly to bodies moving or moved suddenly or violently, and indicating the origin and intensity of the motion, rather than its quantity or effectiveness."  [1913 Webster]
•  Fig.: Impulse; incentive; stimulus; vigor; force; as, the President's strong recommendation provided the impetus needed to pass the campaign reform bill.  Buckle.  [1913 Webster]
•  The altitude through which a heavy body must fall to acquire a velocity equal to that with which a ball is discharged from a piece.  [1913 Webster]

OXFORD DICTIONARY

Impetus, n.
1 the force or energy with which a body moves.
2 a driving force or impulse.

Etymology

L, = assault, force, f. impetere assail (as IN-(2), petere seek)

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.