Synonyms to nailed down

ascertained, actual, appreciated, apprehended, assured, attested, authenticated, borne out, categorically true, certain, certified, circumstantiated, comprehended, conceived, confirmed, corroborated, decided, demonstrated, determinate, determined, discerned, documentary, down pat, effectual, established, factual, fixed, grasped, guaranteed, historical, in the bag, known, made sure, not in error, objectively true, on ice, open-and-shut, pat, perceived, prehended, proved, proven, real, realized, recognized, secure, seized, set, settled, shown, stated, substantiated, sure-enough, tested, tried, true, true as gospel, truthful, unconfuted, undenied, understood, undoubted, unerroneous, unfallacious, unfalse, unmistaken, unquestionable, unrefuted, validated, veracious, verified, veritable, warranted, affianced, arrogant, aspiring, assurance, assuredness, balanced, believing, betrothed, bound, certitude, clear-cut, cocksure, collected, committed, composed, compromised, confidence, confident, contracted, conviction, convinced, cool, covered, defi