Definitions for "Merge field"
A placeholder that you insert in the main document. Merge fields direct Microsoft Word where to insert specific information from the data source. For example, insert the merge field "City" to have Word insert a city name, such as "Paris," that is stored in the City data field.
a placeholder for database values
a placeholder inserted into a main document that instructs Word where to put information that comes from a data source during a mail merge