SUPPOSITIONAL

conjectural, divinatory, hypothetical, hypothetic, supposed, suppositional, suppositious, supposititious

(adjective) 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”

Source: WordNet® 3.1

Etymology

Adjective

suppositional (comparative more suppositional, superlative most suppositional)

Resting on supposition; hypothetical; conjectural.

Source: Wiktionary

Sup`po*si"tion*al, a.

Definition: Resting on supposition; hypothetical; conjectural; supposed. South.

Source: Webster’s Unabridged Dictionary 1913 Edition