Definition of "cathedral"

Relating to the throne or the see of a bishop.  examples

The principal church of an archbishop's/bishop's archdiocese/diocese which contains an episcopal throne.  examples

(loosely or informally) A large or important church building.  examples

(figurative) A large, impressive, lofty, and/or important building or place of some other kind.  examples

A large buttressed structure built by certain termites.  examples

(US politics, slang) In certain right-wing conspiracy theories, the mainstream system or establishment of society, held to be liberal or leftist and to be working against the interests of the people or nation, which is both.  quotations