1. Suppressing or eliminating engine knock in combustion engines
   - antiknock

See also: leaded

• Haemulon album
• Haemulon aurolineatum
• Haemulon macrostomum
• Haemulon malanurum
• Haemulon parra
• hafiz
• hafnium
• haft
• Haftarah
• Haftorah
• hag
• Hagada
• Haganah
• hagberry
• hagberry tree
• hagbut
• Hageman factor
• Hagerstown
• hagfish
• Haggada
• Haggadah
• Haggai
• haggard
• haggardly
• haggis