Top Definition
1. Putting yourself or someone else on a list for an activity, class, etc.
2. When someone is instant messaging you and they suddenly sign off because of something you say (similar to "hang up" on the phone)
guy1: i heard this year mr. herbert is teaching woodshop.
guy2: i have to go sign up for that class!

girl1: what happened last night? you totally signed up on me!
guy3: sorry, my internet connection is horrible.
by gimmieyertots March 22, 2005

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When there is an activity you are forced to do or did not want to do, you would say, "that is a sign up" because you didn't sign for the activity you are being forced to do
My mom told me to clean the poop out of the toilet, thats a sign up.
by Jett Hiu February 08, 2017

The Urban Dictionary Mug

Lotsa space for your liquids.

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The Urban Dictionary Mug

Lotsa space for your liquids.

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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.

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The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

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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