Concepts change their meaning over time, both vertically and horizontally.
A vertical expansion extends the term’s definitional understanding: trauma used to refer to a physical wound incurred during a battle, but now can mean psychological heightened states.
A horizontal expansion extends the context: Once bullying was exclusively top-down abuse (status or physical dominance), yet now it has shifted to be used in a bottom-up context where an employee can bully a boss.
As the concept opens (creeps into society and expands) previous instances can be named, and thus we can attend to them. Yet, the promiscuity of the term allows for abuse as well.
"the art of manliness" podcast – the dangers of concept creep