mother country

1. The country of one's birth or one's ancestors.
2. The country from which the settlers of a territory originally came.

To find a representative American word for the year 1617, when the struggling Jamestown colony was the only English-speaking habitation in North America, we need to travel to Leyden, Holland. There the religious separatists who had left England in 1607 were making plans for the voyage that would establish the Plymouth colony in New England three years later. Two of them, John Robinson and William Brewster, wrote in a letter of December 1617, "We are well weaned from the delicate milke of our mother countrie, and enured to the difficulties of a strange and hard land, which yet in a great parte we have by patience overcome."

England was, of course, the mother of all countries for the English-speaking colonists, and these Americans-to-be were the first to call England the mother country. And the history of the next two centuries would show that the colonists' relationship with the mother country was as touch-and-go as that between any human mother and child.

The noun has one meaning:

Meaning #1: the country where you were born
  Synonyms: fatherland, homeland, motherland, country of origin, native land