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

See also: leaded

• ground-effect machine
• ground-emplaced mine
• ground-floor
• ground-hugging
• ground-service crew
• ground-shaker
• groundball
• groundberry
• groundbreaker
• groundbreaking
• groundbreaking ceremony
• groundcover
• grounder
• groundfish
• groundhog
• Groundhog Day
• grounding
• groundkeeper
• groundless
• groundlessly
• groundlessness
• groundling
• groundmass
• groundnut
• groundnut oil