1. past tense and past participle of deepen; made or became deeper in physical depth
2. made or became more intense, serious, or profound

Examples

• The workers deepened the well to reach the water table.
• The river deepened as it flowed toward the ocean.
• Her voice deepened with emotion as she spoke.
• The economic crisis deepened throughout the year.
• Their friendship deepened over time.
• The mystery deepened when new evidence was discovered.
• The colors deepened as the sun set behind the mountains.