Basil
The word basil comes from the Greek βασιλεύς (basileus), meaning "royal". This is because it is believed to have grown above the spot where St. Constantine and Helen discovered the Holy Cross. The Oxford English Dictionary quotes speculations that basil may have been used in "some royal unguent, bath, or medicine". Basil is still considered the "king of herbs" by many cookery authors. An alternative etymology has "basil" coming from the Latin word basilicus, meaning dragon and being the root for basilisk, but this likely was a linguistic reworking of the word as brought from Greece.