ungodliness: the refusal to give God the reverence he is owed, and the deeds that refusal produces
Greek made this word by putting "not" in front of its family of words for reverence and worship. So it is not a general term for wickedness. It names one specific failure: a person gives God none of the awe, honor, and worship that belong to him. In the Greek cities that counted as a public offense rather than a private opinion, and it was the charge Socrates was tried on. The Greek Old Testament then took the word over to name the whole guilty way of life that stands opposite to being right with God.
Paul's most careful use of it puts it next to a separate word for wrong done to other people (ἀδικία), and says God's anger is revealed against both. That pairing shows what this word contributes: it looks up rather than sideways. Other New Testament words for sin measure a person against the law they broke (ἀνομία) or against the neighbor they harmed. This one measures them against God himself and finds nothing owed to him paid. Its exact opposite belongs to the same family: the devout life that does render God his due (εὐσέβεια), which is why Titus 2:12 can say believers are trained to renounce the one so they may live the other.
The word's two senses are simply the condition and its output. Usually it is the condition: something a person can be trained to renounce, something empty and profane talk drives people deeper into. Twice it goes plural and names the acts and cravings the condition throws up, which is why some English Bibles read "ungodly deeds" where the Greek has a plural noun. Nothing about the word's meaning changes when it does that.
Jude turns the whole family into a drumbeat. In one sentence the Lord comes to convict:
- the godless people themselves (ἀσεβής)
- the deeds their godlessness produced
- the godless manner in which they did them
The repetition adds no new information. It is there for weight, and it makes the point that the fault is not one bad act but a whole way of standing toward God.