churn somebody/something ↔ up phrasal verb ( see also ↑ churn )
1 . churn something ↔ up to damage the surface of the ground, especially by walking on it or driving a vehicle over it:
The lawn had been churned up by the tractor.
2 . churn something ↔ up to move water, mud etc around violently:
The oars had churned up the mud, clouding the water.
3 . British English to make someone upset or angry:
Though she looked calm, in reality she was churned up inside.