I believe it means being in sin but not caring one way or the other about it (not being ashamed of sin).
On 5/17, the Holy Father said:
“Peter was saddened that, for a third time, Jesus asked him, “Do you love me?” This pain, this shame – pa great man, this Peter – [and] a sinner, a sinner. The Lord makes him feel that he is a sinner – makes us all feel that we are sinners.
The problem is not that we are sinners: the problem is not repenting of sin, not being ashamed of what we have done. That’s the problem.
(snip)
“Peter was a sinner, but not corrupt, eh? Sinners, yes, everyone: corrupt, no.
And then yesterday, 6/3, he said:
“These, slowly, slipped on that autonomy, that independence in their relationship with God: ‘We don’t need that Master, who shouldn’t come and disturb us!’ And we go forward with this. These are the corrupt!
These were sinners like all of us, but they have taken a step beyond that, as if they were confirmed in their sin: they don’t need God! But it only seems so, for in their genetic code there is this relationship with God. And since they can’t deny this, they make a special god: they themselves are god. They are corrupt.”
“This is a danger for us, too,” he added. In the “Christian communities,” he said, the corrupt think only of their own group: “Good, good. It’s about us - they think - but, in fact, ‘they are only out for themselves”:
“Judas [was the first]: from a greedy sinner, he ended in corruption. The road of autonomy is a dangerous road: **the corrupt are very forgetful, have forgotten this love, with which the Lord made the vineyard, has made them! They severed the relationship with this love! ** And they become worshipers of themselves. How bad are the corrupt in the Christian community! May the Lord deliver us from sliding down this road of corruption.”
I think the term recalcitrant or reprobate would also apply.