1. substances added to gasoline to prevent engine knocking or pinging
Usage: technical; automotive

Examples

• The refinery added antiknocks to improve the fuel’s octane rating.
• Modern gasoline contains various antiknocks to ensure smooth engine operation.
• Lead-based antiknocks were phased out due to environmental concerns.
• The mechanic recommended using fuel with better antiknocks for the high-performance engine.
• Ethanol serves as one of the common antiknocks in today’s gasoline blends.