positivist, accurate, confirming, hard, inarguable, authentic, positively charged, provable, unassailable, electropositive, positivistic, demonstrable, true, plus, incontestible, undisputable, overconfident, cocksure, prescribed
certain (part of speech: adjective)
clear, confident, steadfast, definite, decisive, incontestable, assured, indubitable, irrefragable, undeniable, veritable, irrefutable, decided, trusting, patent, doubtless, unmistakable, convinced, positive, sure, undoubted, unequivocal, unquestionable, set, absolute, indisputable, certain
- I consider it an incontrovertible truth, that whatever by the constitution government even may do, if it relates to the abuse of power by acts tyrannical and oppressive, it some time or other will do. - "Essays on the Constitution of the United States", Paul Leicester Ford.
- It was very bad Spanish and very absurd, but she thought it delightful, poetical, classical, sentimental, argumentative, convincing, incontrovertible, imaginative, and even grammatical, for if it was not good Spanish, there was no Spanish half so good. - "Mr. Midshipman Easy", Captain Frederick Marryat.
- The fact was incontrovertible. - "Project Gutenberg History of The Netherlands, 1555-1623, Complete", John Lothrop Motley.