suppositious
Americanadjective
Other Word Forms
Etymology
Origin of suppositious
First recorded in 1615–25; shortened form of supposititious
Explanation
Something you assume to be true without having any real proof is suppositious. If there's no evidence that your brother stole your favorite sweatshirt, it's suppositious to accuse him of the deed. When you use supposition, or an unproven belief, to decide something, that's suppositious. Both words come from suppose and its root, which means "to assume." This adjective is uncommon today — you're more likely to say "unfounded" or "based on an assumption." Still, feel free to pull out suppositious for situations such as the suppositious evidence a substitute teacher uses to punish the whole class for passing notes.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
In a year when snooker's maximum break, once considered as suppositious as the Himalayan Yeti, has repeatedly shown up for the cameras, it fell to O'Sullivan to show that nobody does it better.
From BBC ● Dec. 2, 2025
By quotations from suppositious, always unnamed "authorities," by innuendoes and by skilled selection of facts he presumed to prove hat Henry Ford is decaying as a maker of motor cars.
From Time Magazine Archive
I was the mascot of no clique of friends, nor the pawn of scientists who might find a suppositious and mythical glory in the reflected light of another's achievement.
From My Attainment of the Pole by Frederick A. Cook
He is bitten by suppositious dogs cunningly simulated by stage carpenters, who remark "bow wow" from behind the scenes.
From Punchinello, Volume 1, No. 10, June 4, 1870 by Various
They are grounded on some suppositious set of circumstances, and declare how some given cause would operate in those circumstances, supposing that no others were combined with them.
From A System Of Logic, Ratiocinative And Inductive by John Stuart Mill
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