Top Definition
1.A person who has committed a party foul
2. Someone who is a debbie-downer, anti-social, a loser
3. A person who ruins party's
4. Someone who does not know how to have a good time
5. Someone who is a wallflower
Juan decided to stay in and do homework instead of coming out with us on Saturday; He is such a mufflebaby.

Dan forgot to buy the cups for the root game, he is such a mufflebaby.
by Team Honda Civic March 21, 2011

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someone who commits a party foul.

someone who is boring, or a downer.
Lionel won't take this shot with us. He's being such a mufflebaby.
by ehhhh412 March 20, 2011

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt