What does the word Bastard refer to in the bible?
The word "bastard" appears three times in the King James Version of the Bible. In Deuteronomy 23:2 and Zechariah 9:6 the Hebrew word is "mamzer." While that word in Yiddish does sometimes mean an "illegitimate child," the word itself means "mixed." The passages would make equal sense if it is taken to mean a child of a marriage between a Jew and one of the nations the Jews were forbidden to marry. In fact, in Deuteronomy that fits the context best. "A bastard shall not enter into the congregation of the LORD; even to his tenth generation shall he not enter into the congregation of the LORD. An Ammonite or Moabite shall not enter into the congregation of the LORD; even to their tenth generation shall they not enter into the congregation of the LORD for ever."
The other use of the word is in Hebrews 12:8. The whole context is as follows: "And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him: For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth. If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not? But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons. Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live?" (Heb. 12:5-9) The clear meaning of the term here is one who is not the legitimate son of a father. This is what we generally think of when we use the term today.