Strong's G2407 — ἱερατεύω (verb)
hierateuo (hee-er-at-yoo'-o) v.
1. to be a priest, i.e. perform his functions
[prolongation from G2409]
KJV: execute the priest's office 
Root(s): G2409 
Hebrew root: ἱερεύς
Occurrences: 1