“The wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness.” All modern translations render that last phrase with another word: “who suppress the truth.”
In contemporary English, to “hold the truth” means to believe it, to establish it as a tenet for oneself. “We hold these truths to be self-evident…”
The Greek word translated hold (κατέχω) means exactly that in 1 Cor 15. “I would remind you, brothers, of the gospel I preached to you, which you received, in which you stand, and by which you are being saved, if you hold fast to the word I preached to you—unless you believed in vain.”
So the KJV translators certainly have some justification in using the word hold in Rom 1. But what do they think this verse means? There are ungodly people who hold fast to the truth, who take it as a personal tenet—but they do so unrighteously? I suppose that’s possible. But suppress makes much better sense.