1. fraudulently substituted; spurious or counterfeit
Usage: formal; literary
2. hypothetical; based on supposition
Usage: formal

Examples

• The art expert identified the painting as suppositious, not an original masterpiece.
• The will was declared invalid due to suppositious signatures.
• He presented only suppositious evidence to support his theory.
• The suppositious heir had no legitimate claim to the throne.
• Her suppositious argument lacked concrete proof.
• The document appeared to be suppositious rather than authentic.