shun - literally, “stand above,” separate from, and superior to.
vain - opposed to “the truth” (2Ti 2:15).
babblings - with loud voice: opposed to the temperate “word” (Tit 3:9).
increase - Greek, “advance”; literally, “strike forward”: an image from pioneers cutting away all obstacles before an advancing army. They pretend progress; the only kind of progress they make is to a greater pitch of impiety.
more ungodliness - Greek, “a greater degree of impiety.”