Groundswell (noun)

1. A gradual increase in support or popularity of something.
2. A large, long ocean wave caused by a distant storm or underwater earthquake.
3. A strong and growing feeling or movement among a large group of people.

Origin:

From the verb ground (referring to the ground) + swell.

Examples:

1. There was a groundswell of support for the new policy.
2. The groundswell of public opinion was against the war.
3. The storm caused a groundswell that made the boat rock violently.
4. The earthquake caused a groundswell that damaged the coast.
5. The groundswell of discontent among the workers led to a strike.