The term “Billboard” (billboard) appeared in the U.S. more than 100 years ago, when companies began to rent an area on wooden boards for advertisements, or “the Bill”, giving rise to the term “Billboard”.

Where did “billboards” (bigboard), these “big Board”come? It turns out that in the countries of the former USSR in the 90s in the advertising market there was a Big Board(maybe there is now, I don’t know). At the bottom of the billboards was signed “Big Board”, from billboards and had been called billboards.

From all this I concluded that bigboards are called bigboards not because a word is similar with  “billboard” , but because it was previously associated with the company Big Board.