The word "area" refers to the extent or measurement of a surface or space, often expressed in square units. It can also be used to describe a particular region or space, such as a designated area within a building or a specific geographical location. Regarding the clue, based on the missing letters provided, it could be word "acreage" which refers to the area of land measured in acres.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Surface calculation. Explanations are generated by AI and may be inaccurate.