1.AdjectiveRelating to the office of a bishop or an archbishop.
2.NounThe principal church serving as the office (and some as place of residence) of an archdiocese's/a diocese's archbishop/bishop which is symbolized by an episcopal throne known as the cathedra.
"The bishop presided over the ceremony from his seat in the cathedral."
3.NounA large or important church building.
4.NounA large, impressive, lofty, and/or important building or place of some other kind.
"a cathedral of commerce"
5.NounA large buttressed structure built by certain termites.