Ubiquitous means found everywhere, all the time. Something ubiquitous is so common that you can't seem to escape it no matter where you go.

Smartphones have become ubiquitous in modern life: you see them in restaurants, on buses, in parks, and in classrooms. Dandelions are ubiquitous in spring, popping up in lawns across entire neighborhoods. Certain songs become ubiquitous hits, playing in every store and on car radios until you know every word whether you wanted to or not.

A popular toy might sell well, but a ubiquitous toy shows up in every kid's backpack. Pigeons are ubiquitous in cities worldwide, thriving on every continent except Antarctica.

When something becomes ubiquitous, we often stop noticing it precisely because it's so common. Street signs, plastic bottles, and email are all ubiquitous parts of daily life that would have seemed like science fiction to your great-great-grandparents. The word helps us notice and name just how thoroughly something has spread through our world.