Top Definition
To die by jumping in front of an oncoming train. Comes from a combination of New York City subway code for "person under train" (12-9) and shorthand for "yourself" ("12-9 yourself"). Suggestion of how a person "ought to be killed" when one is annoyed with the other person. Similar in meaning to DIAF and DIAT. In other words: "shut up".
"Shut up, DIAF, and 12-9ys, moron. You have flamed enough for the both of us!"
by New Brunswick Station April 11, 2006

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To die by jumping in front of an oncoming train. Comes from a combination of New York City subway code for "person under train" (12-9) and shorthand for "yourself" ("12-9 yourself"). Suggestion of how a person "ought to be killed" when one is annoyed with the other person. Similar in meaning to DIAF and DIAT. In other words: "shut up".
"Shut up, DIAF, and 12-9ys, moron. You have flamed enough for the both of us!"

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.

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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
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