Acclimation is when you adjust to a new climate or situation. You could say that your acclimation to living in a new country has been harder than you expected.
The process of acclimation is all about the way that a person or other organism adapts to a new environment. In science, acclimation describes a specific process, the biological changes an animal or plant makes in response to a change, like trees’ acclimation to an increase in carbon dioxide. In people, acclimation is more about adjusting to something new — like a child’s acclimation to having a new baby sister.