snowball effect
a small thing growing into something big
What it means
A snowball effect is when a small action or event triggers a process that grows steadily in size, importance, or speed. It's used in finance (compound interest), social media (viral posts), debt (mounting balances), and politics — anywhere a tiny push leads to outsized results over time.
Words like “snowball effect” are exactly the kind of vocabulary our English vocabulary size test measures — find out how many English words you know.
Examples
- One viral post had a snowball effect on her follower count.
- Skipping payments creates a snowball effect with credit-card debt.
- Small acts of kindness can have a real snowball effect in a community.
- The product launch had a snowball effect across the whole industry.
Where it comes from
From the 19th-century image of a small snowball rolling downhill, gathering more snow and growing larger as it goes. The metaphorical use for self-reinforcing growth was common in English by the late 1800s.
Related idioms
🎓 Think you know your idioms?
Take the English Idioms Test — 20 terms, instant result, no signup.
Take the English Idioms TestBuilt by the team behind Deep In.