1. (of theories etc) incapable of being defended or justified
   - indefensible

See also: unreasonable

• dioxane
• dioxide
• dioxin
• dip
• dip circle
• dip into
• dip solder
• DIP switch
• dipeptide
• diphenhydramine
• diphenyl
• diphenylbutyl piperidine
• diphenylhydantoin
• diphtheria
• diphtheritic
• diphthong
• diphthongal
• diphthongise
• diphthongize
• Diphylla
• Diphylla ecaudata
• Dipladenia
• Dipladenia boliviensis
• Diplazium pycnocarpon
• diplegia