Definition
An impetus is the push that gets something going or keeps it moving. A new law can give impetus to clean energy; a crisis can be the impetus for reform. The word comes from the Latin for 'attack, impulse', and it keeps that sense of a driving force applied at the right moment — the shove that turns intention into motion. Once enough impetus is behind a movement, it can carry forward under its own weight.
Examples
Collocations
give impetus to·provide the impetus·fresh impetus·the impetus for change·gather impetus
Synonyms
stimulus·impulse·drive·motivation·momentum
Antonyms
hindrance·obstacle
Word family
impetuous (adjective)
In TOEFL & IELTS
A favorite of IELTS Writing Task 2 on change and development: 'give impetus to', 'provide the impetus for'. It is an uncountable noun used with give/provide/gain. Don't confuse it with the related adjective 'impetuous' (acting rashly on impulse). Stress falls on the first syllable: IM-pe-tus.