Definition
Momentum is motion's refusal to stop. In physics it is mass times velocity — the measure of how hard a moving thing is to halt — and the figurative sense keeps that arithmetic: a campaign, reform, or career 'gains momentum' as each success makes the next one cheaper, until the effort is no longer in moving but in stopping. From the Latin movere, 'to move'. Momentum is borrowed force: the push you gave yesterday, still paying for today's progress.
Examples
- The campaign gained momentum after the first televised debate.
- Reforms lost momentum once the crisis that inspired them had passed.
- The boulder rolled downhill, gathering momentum with every meter.
Collocations
gain momentum·gather momentum·lose momentum·maintain the momentum·the momentum behind
Synonyms
impetus·drive·thrust·traction·propulsion
Antonyms
standstill·stagnation·inertia
In TOEFL & IELTS
Double-duty vocabulary: TOEFL physics lectures use the literal sense, while history and social passages narrate movements that 'gained momentum' — a signpost that change is accelerating. For IELTS essays, 'maintain the momentum of reform' is a high-band phrase. The testable part is the verb company it keeps: gain, gather, build, lose, sustain. No useful derived forms — 'momentous' means important, a different word in practice.