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

See also: unsupported

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• whizzbang
• who
• who'd
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• whoever
• whole
• whole blood
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• whole cloth
• whole gale
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• whole kit and boodle
• whole kit and caboodle
• whole life insurance
• whole meal flour