(adjective)
not having a fixed date from one year to the next, but rather occurring on a changing/variable date, used to describe a festival or holiday;
e.g. This occasion is observed with a movable feast whose date depends on the lunar calendar.
(noun)
something, especially an appliance of a piece of furniture, that can be moved or removed from a building, as opposed to one that is fixed in position by being attached to the floor/walls;
e.g. The sofa is the largest movable that we have to take away in the truck.