basil n.

fabulous lizard-like creature, c. 1400, earlier basiliscus (Trevisa, late 14c.), from Latin basiliscus, from Greek basiliskos name of a kind of serpent, also the golden-crested wren, literally "little king," diminutive of basileus "king" (see Basil); said by Pliny to have been so called because of a crest or spot on its head resembling a crown.

The basilisk has since the fourteenth century been confused with the Cockatrice, and the subject is now a complicated one. [T.H. White, "The Bestiary. A Book of Beasts," 1954]

Its breath and glance were said to be fatal. The South American lizard was so called (1813) because it, like the mythical beast, has a crest. From 1540s as a type of large cannon throwing shot of 200 lb.

1540s, "type of building based on the Athenian royal portico, large oblong building with double columns and a semicircular porch at the end," from Latin basilica "building of a court of justice," from Greek (stoa) basilike "royal (portal)." In Athens this was the portico of the archon basileus, the official who dispensed justice there. The word is thus from the fem. adjective of basileus "king" (see Basil).

In Rome, the style of building used for halls of justice, many of which were subsequently appropriated as churches, and so it became a standard plan for new churches. The word is applied to the seven principal Roman churches founded by Constantine. The specific reference to Christian churches in English is attested by 1560s.