To kindle, inflame, or burn intensely. Used in Romans 1:27 of the burning passion that Paul describes as the consequence of idolatry — when people exchange the natural for the unnatural, their passions are inflamed in disordered directions.
Ekkaiō appears in Romans 1's analysis of the downward spiral of human sin. Paul's argument is not primarily about sexual ethics but about the logic of idolatry: when the creature is worshiped in place of the Creator, the image of God in humanity becomes distorted at every level — including desire itself. The 'burning' (ekkaiō) of Romans 1:27 is the inflamed, out-of-control passion that results from exchanging truth for the lie. Paul's diagnosis is pastoral as much as moral: these are people who have been handed over to the consequences of abandoning God.