knapskull, knapscull or knapscal /napˈskəl/ (obs Scot)

A kind of helmet

• Diophantine analysis
• Diophantine equation
• Diophysite
• diopside
• diopsides
• dioptase
• dioptases
• diopter
• diopters
• dioptrate
• dioptre
• dioptres
• dioptric
• dioptrical
• dioptrics
• diorama
• dioramas
• dioramic
• diorism
• diorisms
• dioristic
• dioristical
• dioristically
• diorite
• diorites