Acclimatization can be understood as the adapation of a plant from one environment to another: for example, the change from its area of cultivation or a greenhouse to the inside of a commercial centre or to some other locality. How long it takes to adapt depends on the species, the conditions in which it has been growing and the extent to which its surroundings change.
It is in their production areas that palms find the optimum conditions for growth, and so when they are transferred directly to an indoor ambience, they will suffer the loss of a certain amount of foliage, and may stop growing or even die. So when acquiring plants it is of great benefit to find out what conditions they were cultivated in.