The term Peter uses appears in the Old Testament to render such Hebrew terms as scornful, haughty, insolent.
Persons with this mindset think of themselves as self-sufficient and hence not needing God—and indeed big enough to go toe-to-toe with God. It’s the attitude Pharaoh displayed (Exodus 5:2). In the plagues that followed the Lord scorned the scornful (as the Hebrew of Proverbs 3:34 has it) and destroyed Pharaoh’s pride.
5 Likewise, you who are younger, be subject to the elders. Clothe yourselves, all of you, with humility toward one another, for “God opposes the proud but gives grace to the humble.”