Is there a name for this common type of blunder? I'm sure most of us have done it at least once ... I had a position where one of my pieces were under direct threat - I was a pawn up, but my opponent attacked my rook with his bishop and threatened to get the pawn back if I was careless. I tried to calculate every possible continuation and got lost in the possibilities ... and before I knew it, I was totally absorbed by the position 4 or 5 moves ahead and completely forgot that my rook was hanging. Keeping a mental eye on the future position instead of the position in front of me, I made a silly move (moved my knight, if I recall) and lost my rook.

Naturally, and quite embarrassingly, my teammates all wanted to know what happened since it looked so good for me at one point. Instead of trying to explain the intricacies of the position, it would be convenient if I could tell my club mates that I lost because of an "X-blunder". Does this type of blunder have a name?
It is probably a bit more general than what you describe, but one move blunders are often called (a case of) "chess blindness". 

I'm not a hundred percent sure, what exactly happened in you're case but often people make the second move of a combination (or variation) first, because they are ahead of the actual position. But I don't know a succinct term for that.

If you listen to top players post game interviews, what you hear incredibly often is "I just forgot about move xy". I guess if that description is good enough for Aronian and Co, it is good enough for us. ;-)

Another loosely connected term is "residual image". This describes the case when you are calculating and pieces that already moved, are still on their original square in your mind.