Related Clues:

• Hard to dispute, as a theory
• Like a solid argument
• Forceful, as an argument
• Solidly based
• Like a well-armed fort
• Forceful and persuasive
• Convincing, persuasive
• Compelling or convincing
• Powerful and convincing, argument say
• Forceful and convincing
• Of argument, rational and defensible
• Forceful and to the point
• Able to be defended against attack or objection
• Convincing and compelling
• Powerfully persuasive, argument say