Squalid means extremely dirty, run-down, and unpleasant because of neglect or poverty. A squalid apartment might have peeling paint, broken windows, trash piling up, and grime covering every surface. A squalid alley might be littered with garbage, puddles of murky water, and crumbling walls covered in mold.

The word describes conditions that make you uncomfortable just thinking about them: filthy, depressing, and unhealthy. It's stronger than just “messy” or “dirty.” Your bedroom might be messy with clothes on the floor, but it's not squalid. A place becomes squalid when it's been neglected for so long that the dirt, decay, and disorder feel overwhelming.

In Charles Dickens's Oliver Twist, Oliver escapes squalid conditions in a London workhouse, where orphans lived in crowded, filthy rooms with barely enough food to survive. The word helps readers picture just how terrible those conditions were.

Squalid can also describe situations or behaviors that seem morally shabby or contemptible, like a squalid scheme to steal money from unsuspecting people. Whether describing a physical place or a person's actions, the word suggests something deeply unpleasant that deserves much better.