Antonyms of adj suppositious

1 sense of suppositious

Sense 1
conjectural, divinatory, hypothetical, hypothetic, supposed, suppositional, suppositious, supposititious -- (based primarily on surmise rather than adequate evidence; "theories about the extinction of dinosaurs are still highly conjectural"; "the supposed reason for his absence"; "suppositious reconstructions of dead languages"; "hypothetical situation")

INDIRECT (VIA theoretical) -> empirical, empiric -- (derived from experiment and observation rather than theory; "an empirical basis for an ethical theory"; "empirical laws"; "empirical data"; "an empirical treatment of a disease about which little is known")

Similarity of adj suppositious

1 sense of suppositious

Sense 1
conjectural, divinatory, hypothetical, hypothetic, supposed, suppositional, suppositious, supposititious -- (based primarily on surmise rather than adequate evidence; "theories about the extinction of dinosaurs are still highly conjectural"; "the supposed reason for his absence"; "suppositious reconstructions of dead languages"; "hypothetical situation")
       => theoretical (vs. empirical), theoretic -- (concerned primarily with theories or hypotheses rather than practical considerations; "theoretical science")