1. Not imagined even in a dream
   - undreamed, undreamed of, undreamt of, unimagined

See also: incredible, unbelievable

• four-petaled
• four-petalled
• four-ply
• four-poster
• four-pounder
• four-pronged
• four-sided
• four-spot
• four-stroke engine
• four-stroke internal-combustion engine
• four-tailed bandage
• four-wheel
• four-wheel drive
• four-wheeled
• four-wheeler
• four-wing flying fish
• four-year-old
• fourchette
• Fourdrinier
• fourfold
• fourfold point correlation
• fourhanded
• Fourier
• Fourier analysis
• Fourier series