GOP is an acronym standing for 'Grand Old Party'. It is commonly used to refer to the Republican Party in the United States. According to the Republican National Committee the acronym dates back to 1875, when it originally meant 'Gallant Old Party".
It started out in 1875 as initials for Gallant Old Party which was the nickname for
the Republican Party. Over the years, they turned into meaning Grand Old Party
and the intials eventually got shortened totally to GOP.
GOP stands for "Grand Old Party. " It doesn't mean anything especially. The expression "gallant old party" dates from 1875, "grand old party" from 1876, "G. O. P. " from 1884.