Thayer's Greek Lexicon

 Cyrenius = "warrior"
1. the Greek form of the Roman name Quirinus. His full name is
Publius Sulpicius Quirinus. He was consul B.C. 12., and was made
governor of Syria after the banishment of Archelaus in A.D. 6. He
was probably twice governor of Syria; his first governorship
extended from B.C. 4 (the year of Christ's birth) to B.C. 1. It
was during this time that he was sent to make enrolment which
caused Joseph and Mary to visit Bethlehem. Luke 2:2. The second
enrolment is mentioned in Acts 5:37.