Welcome to English in a Minute. To get rid of something can mean to throw something away.
But what do you think good riddance means?
My roommate is moving out.
You mean the roommate who eats your food, never cleans up, and owes you thousands of
dollars in rent money? I say good riddance.
Well he's my friend too, Anna.
Dan, he may be a good friend, but he is a terrible roommate.
Good riddance is used to express relief at being free from a troublesome person or thing.
It means you are glad that someone is leaving or something is over.
I've got to agree with Anna. Dan, you deserve better.