Caecilius

The Roman family name that gave rise to Cecil. It is unused on modern boys, although it would be a very offbeat way to get Kai as a nickname.

For several generations of British schoolchildren, this name is forever associated with the Cambridge Latin Course textbooks, whose opening line is "Caecilius est in horto" (Caecilius is in the garden).

Pronounced kai-SIL-yus.