To consecrate something is to make it holy and dedicate it to the service of the divine. This may be done to an area as in creating sacred space, a ceremonial tool or offering or a person, such as clergy.
Often an item is cleansed using water or smoke first and then consecrated through a ceremony involving a declaration that this item (person, place or thing) is dedicated to the service of a specific God or group of Gods or a sacred purpose.
The word Consecrate is often used synonymously with the word Sanctify.