1. Impossible to deny or disprove
   "an irrefutable argument"
   - incontrovertible, positive

See also: undeniable

• Xyphophorus
• Xyphophorus helleri
• Xyridaceae
• Xyridales
• Xyris
• Xyris operculata
• xystus
• XYY
• y
• Y chromosome
• y'all
• y'know
• y-axis
• Y-fronts
• Y-linked gene
• Y-shaped
• Y2K
• Y2K compliant
• ya
• yabber
• yacca
• yacca podocarp
• yacht
• yacht chair
• yacht club