Answer: unus

AnswerCrossword Clue
UNUSone, to Cicero
UNUSOne: Latin.
UNUSOne: Lat.
UNUSLatin number.
UNUSLatin numeral.
UNUSLatin one.
UNUS..., duo, tres
UNUSRingling star who balanced on one finger
UNUSFormer Ringling star
UNUS"... pro omnibus, omnes pro uno"
UNUS... the Untouchable ("X-Men" villain)
UNUSOctavian's one