Reprobate
The Greek Biblical word, "Adokimos" translated as "reprobate" means "not acceptable." The prefix "a" means "not" and "dokimos" is from a Greek word relating to "anything which has passed a series of tests," as in proving a metal is pure gold.
"Dokimos" itself is from the Greek verb "dokeo," meaning to "have an opinion about," or to "think."
So "adokimos" could also mean "unthinkable." When people think they are smarter than God is and don't need him anymore, they don't rightly think at all.
God did not give the people up because they were homosexual by orientation. God gave them up because they practiced idolatry just like the Canaanites did as outlined in the three Chapters of Leviticus 18 through 20 which must be read as one unit. The beginning verses of chapter 18 are restated or rephrased in the ending verses of chapter 20.