If something is done squalidly, it is done in a very dirty and unpleasant way.
The word squalidly makes people think of filth, poverty, and sadness.
Examples:
The room was cleaned squalidly.
He lives squalidly in a small, dirty room.
She cooked squalidly and the food was not good.
The dog ate squalidly and made a mess.
The villain squalidly plotted to steal the treasure.
The old house was squalidly dirty and falling apart.