Strong's #544: apeitheo (pronounced ap-i-theh'-o)
 from 545; to disbelieve (wilfully and perversely):--not believe, disobedient, obey not, unbelieving.
Thayer's Greek Lexicon:
 ̓́ 
 
  apeitheō 
 
 1) not to allow one' s self to be persuaded
 
 1a) to refuse or withhold belief
 1b) to refuse belief and obedience
 
 2) not to comply with
 
  Part of Speech: verb
Relation: from G545
  Citing in TDNT: 6:10, 818
 
Usage:
This word is used 16 times:
John 3:36: "everlasting life: and  he that believeth not the Son shall not see"
Acts 14:2: "But the  unbelieving Jews stirred up the Gentiles, and"
Acts 17:5: "But the Jews  which believed not, moved with envy, took unto them certain"
Acts 19:9: "divers were hardened, and  believed not, but spake evil of that way before the"
Romans 2:8: "But unto them that are contentious, and  do not obey the truth,"
Romans 10:21: "my hands unto  a disobedient and gainsaying people."
Romans 11:30: "ye in times past have  not believed God, yet have now obtained mercy"
Romans 11:31: "have these also now  not believed, that through your mercy they"
Romans 15:31: "That I may be delivered from  them that do not believe in Judea; and that"
Hebrews 3:18: "his rest, but  to them that believed not?"
Hebrews 11:31: "Rahab perished not  with them that believed not, when she had received the spies with"
1 Peter 2:7: "which believe he is precious: but  unto them which be disobedient, the stone which the builders"
1 Peter 2:8: "stumble at the word,  being disobedient: whereunto also they were appointed."
1 Peter 3:1: "husbands; that, if any  obey not the word, they also may without"
1 Peter 3:20: "Which sometime  were disobedient, when once the longsuffering of God waited"
1 Peter 4:17: "what shall the end  be of them that obey not the gospel of God?"