quattuorvir
A member of a quattuorvirate; one of four people associated in some office.
historical
The quattuorviri probably took up office on January 1st 44 B.C., although some authorities believe this event took place in October 45 B.C.
Where it comes from
Learned borrowing from Latin quattuorvir.
Adapted from the Wiktionary entry quattuorvir (CC BY-SA 4.0).