Clarus was definitely used as a cognomen in the Roman empire:
http://en.wikipedia.org/wiki/List_of_Roman_cognomina
And, in fact, there were two 2nd century Roman consuls who bore it, Erucius Clarus and Erucius Clarus II:
http://en.wikipedia.org/wiki/List_of_early_imperial_Roman_consuls#2nd_century
Edited to take hyperlinks off of 'Roman' and to fix "1st century" to "2nd" (duh!) :)
~ Ivayla,
skillfully disguised as a responsible adultThis message was edited 5/26/2006, 9:42 AM