Chandler's "wobble"... is my favorite... as in, did you just feel that ?? The earth wobbled just as I fired that shot! (that missed!!).
It's the slight, imperceptable "wobble" of the earth on it's axis as it rotates. Such as a top will "wobble" as it spins on an irregular surface.
Known to happen just as the trigger is pulled causing the target to "move" in relation to the trajectory of the bullet while the bullet is in flight.
It's especially bad on match days when numerous bullets are fired in close proximity.