1. Without a basis in reason or fact
   "the allegations proved groundless"
   - baseless, idle, unfounded, unwarranted, wild

See also: unsupported

• promoter
• promotion
• promotion system
• promotional
• promotional expense
• promotional material
• promotive
• prompt
• prompt box
• prompt copy
• promptbook
• prompter
• prompter's box
• prompting
• promptitude
• promptly
• promptness
• promulgate
• promulgated
• promulgation
• promulgator
• promycelium
• pronate
• pronation
• pronator