basilica (n.) Look up basilica at Dictionary.com
1540s, from Latin basilica "building of a court of justice," and, by extension, church built on the plan of one, from Greek (stoa) basilike "royal (portal)," the portico of the archon basileus, the official who dispensed justice in Athens, from basileus "king" (see Basil). In Rome, applied specifically to the seven principal churches founded by Constantine.