1. moved backward or returned to an earlier, less advanced state
Usage: past tense and past participle of regress
2. returned to childlike behavior or an earlier stage of psychological development
Usage: psychology

Examples

• The patient’s condition regressed after stopping the medication.
• His reading skills regressed during the summer break.
• The country regressed to authoritarian rule after the coup.
• Under stress, she regressed to childhood behaviors.
• The tumor regressed significantly with treatment.
• Economic growth regressed during the recession.
• The child regressed in potty training after the move.