also: バジリカ
noun
basilica
Refers to a large, important church building in Christian architecture, especially in Roman Catholic and Orthodox traditions. Also used for ancient Roman public buildings.
サン・ピエトロ大聖堂はバシリカの一つです。
St. Peter's Basilica is one of the basilicas.
古代ローマのバシリカは裁判所として使われていました。
Ancient Roman basilicas were used as courthouses.
教会 is the general word for 'church' (building or congregation), whereas バシリカ denotes a specific type of monumental church.
Borrowed from Latin 'basilica', via English or other European languages. The two katakana forms reflect different source pronunciations.