cathedral (n.)

1580s, "church of a bishop," from phrase cathedral church (c. 1300), partially translating Late Latin ecclesia cathedralis "church of a bishop's seat," from Latin cathedra "an easy chair (principally used by ladies)," also metonymically, as in cathedrae molles "luxurious women;" also "a professor's chair;" from Greek kathedra "seat, bench," from kata "down" (see cata-) + hedra "seat, base, chair, face of a geometric solid," from PIE root *sed- (1) "to sit."

It was born an adjective, and attempts to force further adjectivization onto it in 17c. yielded cathedraical (1670s), cathedratic (1660s), cathedratical (1660s), after which the effort seems to have been given up.

updated on October 22, 2017

Definitions of cathedral from WordNet
cathedral (n.)
any large and important church;
cathedral (n.)
the principal Christian church building of a bishop's diocese;
Synonyms: duomo
cathedral (adj.)
relating to or containing or issuing from a bishop's office or throne;
a cathedral church
Etymologies are not definitions. From, not affiliated with etymonline.