suppositious

/ˌsʌpəˈzɪʃəs/
adjective
  1. Based on assumption or guesswork rather than fact; hypothetical.
    • The detective dismissed the suppositious theory because there was no evidence.
    • Her argument was entirely suppositious, built on rumors and not on data.
    • In science class, we discussed suppositious scenarios about life on other planets.
What does "suppositious" mean? | whatsthatwordmean | whatsthatwordmean