The online slang dictionary defines the word thus:
juke |joōk| informal
verb [ intrans. ]
1 to cheat.
2 to not meet someone as planned; to "stand up."
3 to fake out or to feign [sports].
4 to dance provocatively.
The applicable definition here is #3. In basketball, to "juke the defender" means to fake a shot (to get the defender to leave his feet) and, while the defender is in the air, drive by him. In football, the "juke" is a weaving or swerving pattern used by receivers to lose their defenders. In both cases, the offensive person make a move to get the defender to hesitate, and then takes advantage.
It happened in traffic the other evening, coming home. I was trying to move into the left lane in traffic to get into a left-turn-only lane. I had my arm out, and two cars had passed me by (the second one made me a little angry -- he had plenty of time to see me and give me room.) The guy in the third car was going to try and sneak by (I was "just a cyclist", after all) but I crowded him, swerved ever so slightly into his lane and he backed off. He didn't want to -- he gave me quite the dirty look as he passed me by on the right. When I saw what he was driving, (a Mercedes S-class) I gave myself a couple of bonus points, as I suspect he wasn't used to getting backed down by drivers in lesser cars, much less a cyclist.
This ability to make a split-second judgement about what a driver is doing (or likely to do) is one of, if not the most challenging aspect of vehicular cycling.
Particularly in this situation -- drivers wouldn't dream of overtaking a car slowing down with its left turn-signal on, but many, many drivers think they can sneak by a cyclist doing exactly the same thing. Although it helps to be taking the lane pretty aggressively, I've still had drivers zoom by me when I'm full in the lane with my arm out. I can't explain this level of motorist negligence.
I don't know how this is taught in the LAB classes (as I've not been able to attend one yet, but that's another story). I think it is one of the most "athletic" aspects of VC, so the athletic analogy is well-suited here.