What's In a Name?
by John Picur

By Grand Central Station, I presume you intend to refer to the union station that existed in downtown Chicago until demolished in 1971.  Grand Central Station operated as a passenger train terminal from 1890 to 1969.  It served, primarily, B&O, CGW, PM and MStP&SSM (Soo Line).  Briefly, it also served NYC and CRI&P when LaSalle St. Station was being rebuilt, 1900-1903.  It was the smallest of the Chicago passenger terminals, serving (in 1912) only 4.5% of Chicago's intercity passengers.

Otherwise ... New York Central's terminal in New York NY is only properly called Grand Central Terminal.  Its predecessor was Grand Central Depot.  I can find no historical trace of there ever being a Grand Central Station in New York City.

Although the uninformed public often mistakenly refers to Grand Central Terminal as "Station", the term is, and has always been, incorrect.

Rebuttal
by Mark Tomlonson

"November 1, 1872 The New York Central & Hudson River, New York & Harlem and New Haven railroads sign an agreement for the joint use of the first Grand Central Station."

At the time the agreement was signed in 1872, the New York City terminus was known as "Grand Central Station" or "Grand Central Depot".

When that building was replaced in 1913, the new building was also called "Grand Central Station" at first, then then name was changed to "Grand Central Terminal" before the last brick was laid. It is still properly called "Grand Central Terminal".