mother church

noun

Definition of mother church

1 archaic : a parish church the mother churches … and rural chapels in the late Saxon and early Norman periodsBulletin of Institute of Historical Research
2 : the principal church of a locality or land specifically : a cathedral or a metropolitan church the mother church … which no visitor to these parts should fail to see — T. I. Ellis
3 : the original church from which others have sprung the mother church of Unitarianism in America— Leo Pfeffer
4 : the original church or communion in which a person has been nurtured returning to his mother church, he died in obscurity— K. S. Latourette