acceleration
activity
animation
ardor
brio
briskness
catalyst
clout
compulsion
drive
driving force
elan
encouragement
energy
enthusiasm
force
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
thrust
impetuous
attraction
breakthrough
disadvantage
fascination
inducement
jolt
onslaught
provocation
rapidity
reinforcement
shove
stimulus
surge
temptation
upheaval
urge
vitality