Sentence:  The new interchange among the four Los Angeles freeways , including the grade-constructed accesses , occupies by itself no less than eighty <WSD>acres</WSD> of downtown land , one-eighth of a square mile , an area about the size of Rockefeller Center in New York . 
Meaning of the word marked with <WSD> tags:  a unit of area (4840 square yards) used in English-speaking countries