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