I'm assuming it simply refers to Unit Movement, i.e. if you're moving around a hex where an enemy unit is stationed, that unit has its movement reduced from 2 to 1. The interesting thing will be mounted units and whether they have a movement reduced from 3 to 2, or from 3 to 1; I'm guessing the former, but I'm not sure. As for movement or attack... I'm assuming you can do either with you 1 point of movement.