Strong's #4754: strateuomai (pronounced strat-yoo'-om-ahee)
 middle voice from the base of 4756; to serve in a military campaign; figuratively, to execute the apostolate (with its arduous duties and functions), to contend with carnal inclinations:--soldier, (go to) war(-fare).
Thayer's Greek Lexicon:
 ́ 
 
  strateuomai 
 
 1) to make a military expedition, to lead soldiers to war or to battle, (spoken of a commander)
 2) to do military duty, be on active service, be a soldier
 3) to fight
 
  Part of Speech: verb
Relation: middle voice from the base of G4756
  Citing in TDNT: 7:701, 1091
 
Usage:
This word is used 7 times:
Luke 3:14: "And  the soldiers likewise demanded of him, saying, And what"
1 Corinthians 9:7: "Who  goeth a warfare any time at his own charges? who planteth a vineyard,"
2 Corinthians 10:3: "in the flesh, we do not  war after the flesh:"
1 Timothy 1:18: "that thou by them  mightest war a good warfare;"
2 Timothy 2:4: "No man  that warreth entangleth himself with the affairs of this life; that he may please"
James 4:1: "even of your lusts  that war in your members?"
1 Peter 2:11: "from fleshly lusts, which  war against the soul;"