1. In an obvious and provable manner
   "his documentary sources are demonstrably wrong"
   - provably, incontrovertibly, irrefutably

See also: demonstrable

• speechless
• speechlessly
• speechlessness
• speechmaker
• speechmaking
• speechwriter
• speed
• speed bump
• speed camera
• speed cop
• speed dating
• speed demon
• speed freak
• speed hump
• speed indicator
• speed limit
• speed of light
• speed skate
• speed skating
• speed trap
• speed-reading
• speedball
• speedboat
• speeder
• speedily