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1.
Abbreviation for "I Do Not Approve"

This abbreviation is the negation to I Approve.

Usually when something terrible happens. This varies from but is not limited to: an old grandma/grandpa wearing a thong at the beach or remaining stuck in a parallel parking spot because the two douches left you no room to leave.
Scenario 1:
Chick 1: Holy fu..

Person 2: What happened?

Chick 1: Don't look behind you..

Person 2: Why not? *looks* Ahh! Seriously is that old dude wearing a banana hammock?

Chick 1: That killed me a little on the inside, IDNA.

Scenario 2:

Man, this is dirty how am I suppose to get out of the parking spot?? IDNA. Oh well, they can say goodbye to their shiny new rims.
by Random Stef April 08, 2010