systemic

meaning in plain English

Affecting the whole thing, not just a small part of it.

Think of a system-wide flu: a systemic illness spreads through the whole body, not just one spot.

for example

The company’s systemic problems meant every department had to change how it worked.

Imagine a stain spreading through an entire white shirt instead of just one corner. That’s how systemic issues work—they’re not just in one spot, they’re everywhere in the system.