The prefixde- in this case would not be a negating prefix but one indicating outward motion as seen in the Latin preposition de, 'down from, from'. Ah! Merci.

Branny, there is another verb meaning for card, at least around these parts. If you look like you could be under the legal age for drinking (or perhaps other things), you get carded at the entrance--meaning they look at your identification card. I don't know if it's just slang or whether it might be in a dictionary somewhere.