1. to treat beforehand, especially to prepare something for a subsequent process or treatment
Usage: technical

Examples

• The fabric must be pretreated with a special solution before dyeing.
• Doctors pretreat cancer patients with medication to reduce side effects.
• The metal surface was pretreated to prevent corrosion.
• We need to pretreat the stain before washing the shirt.
• The water is pretreated with chemicals before entering the filtration system.
• The wood should be pretreated with primer before painting.