1. containing less alcohol than the standard or required amount
Usage: technical; used of alcoholic beverages

Examples

• The whiskey was rejected because it was underproof.
• Underproof spirits cannot be sold as premium products.
• The distillery had to redistill the underproof batch.
• Quality control detected that the rum was underproof.
• Underproof alcohol has a lower concentration than expected.
• The regulations specify that underproof beverages must be labeled accordingly.