accuracy, truth - the quality of nearness to the truth or the true value; "he was beginning to doubt the accuracy of his compass"; "the lawyer questioned the truth of my account"

precision, preciseness - the quality of being reproducible in amount or performance; "he handled it with the preciseness of an automaton"; "note the meticulous precision of his measurements"

trueness - exactness of adjustment; "I marveled at the trueness of his aim"