Strong's G4961 — συστρατιώτης (noun)
sustratiotes (soos-trat-ee-o'-tace) n.
1. a co-campaigner
2. (figuratively) an associate in Christian toil
[from G4862 and G4757]
KJV: fellowsoldier 
Root(s): G4862, G4757 
Hebrew root: στρατιώτης
Occurrences: 2