G4754 στρατεύομαι (strateúomai)

KJV renderings: soldier, (go to) war(-fare)
Strong's definition: to serve in a military campaign; figuratively, to execute the apostolate (with its arduous duties and functions), to contend with carnal inclinations
Derivation: middle voice from the base of G4756 (στρατιά);

From James Strong's public-domain dictionaries (G), JSON edition by OpenScriptures (CC-BY-SA). Every dotted-underline word in the text links here.