- 1Make or become deep or deeper: [no object]: the crisis deepenedMore example sentences
- It seems that Britain's upmarket retailers suffered most and will suffer further if the crisis deepens.
- Local primary schools have issued an urgent cry for help as the schools crisis in the town deepens.
- Beyond the plush-velvet-curtained windows, the darkness and the fog deepen, and a weeping drizzle of rain begins to fall.
- 1.1(Of a weather system) decrease in barometric pressure: Compare with fill. (as adjective deepening) a deepening depression