Strong's #1060: bkowr (pronounced bek-ore')
 from 1069; firstborn; hence, chief:--eldest (son), firstborn(-ling).
Brown-Driver-Briggs Hebrew Lexicon:
 ּ 
  bekôr 
 
 1) firstborn, firstling
 
 1a) of men and women
 1b) of animals
 1c) noun of relation (figuratively)
 
  Part of Speech: noun masculine
Relation: from H1069
Usage:
This word is used 117 times:
Genesis 10:15: "begot Sidon  his firstborn, and Heth,"
Genesis 22:21: "Huz  his firstborn, and Buz and Kemuel the father of Aram,"
Genesis 25:13: "of Ishmael, according to their generations:  the firstborn of Ishmael, Nebajoth; and Kedar, and Adbeel,"
Genesis 27:19: "his father, am Esau  thy firstborn; I have done according as thou biddest"
Genesis 27:32: "And he said, I am thy son,  thy firstborn Esau."
Genesis 35:23: "of Leah; Reuben, Jacob's  firstborn, and Simeon, and Levi, and Judah, and Issachar,"
Genesis 36:15: "of Esau: of Eliphaz  the firstborn son of Esau; duke Teman, duke"
Genesis 38:6: "took a wife for Er  his firstborn, whose name was Tamar."
Genesis 38:7: "And Er, Judah's  firstborn, was in the sight of the LORD; and the LORD"
Genesis 41:51: "called the name  of the firstborn Manasseh: For God, said he, hath made me forget"
Genesis 43:33: "And they sat before  him, the firstborn according to his birthright, according to his youth: and the men marveled"
Genesis 46:8: "and his sons: Reuben, Jacob's  firstborn."
Genesis 48:14: "guiding his hands wittingly; for Manasseh  was the firstborn."
Genesis 48:18: "my father: for this  is the firstborn; put thy right hand upon his head."
Genesis 49:3: "Reuben, thou  art my firstborn, my might, of my strength, the excellency of dignity,"
Exodus 4:22: "the LORD, Israel is my son,  even my firstborn:"
Exodus 4:23: "will slay thy son,  even thy firstborn."
Exodus 6:14: "houses: of Reuben  the firstborn of Israel; Hanoch, and Pallu, Hezron,"
Exodus 11:5: "And all  the firstborn in the land of Egypt from the firstborn of Pharaoh"
Exodus 11:5: "in the land of Egypt from the firstborn  from the firstborn of Pharaoh that sitteth upon"
Exodus 11:5: "that sitteth upon his throne, even unto  the firstborn of the maidservant that is behind"
Exodus 11:5: "that is behind the mill; and all  the firstborn of beasts."
Exodus 12:12: "and will smite all  the firstborn in the land of Egypt, both man"
Exodus 12:29: "that at midnight the LORD smote  the firstborn in the land of Egypt, from the firstborn"
Exodus 12:29: "the firstborn in the land of Egypt, from the firstborn  from the firstborn of Pharaoh that sat"
Exodus 12:29: "of Pharaoh that sat on his throne unto  the firstborn of the captive that"
Exodus 12:29: "the firstborn of the captive that was in the dungeon; and all  the firstborn of cattle."
Exodus 13:2: "Sanctify unto me all  the firstborn, whatsoever the womb among the children of Israel,"
Exodus 13:13: "redeem it, then thou shalt break his neck: and all  the firstborn of man among thy children shalt thou redeem."
Exodus 13:15: "that the LORD slew all  the firstborn in the land of Egypt, both the firstborn"
Exodus 13:15: "the firstborn in the land of Egypt, both the firstborn  both the firstborn of man, and the firstborn of beast:"
Exodus 13:15: "of Egypt, both the firstborn of man,  and the firstborn of beast: therefore"
Exodus 13:15: "all that openeth the matrix, being males; but all  the firstborn of my children I redeem."
Exodus 22:29: "delay to offer the first of thy ripe fruits, and of thy liquors:  the firstborn of thy sons shalt thou give"
Exodus 34:20: "him not, then shalt thou break his neck. All  the firstborn of thy sons thou shalt redeem. And none shall appear"
Leviticus 27:26: "Only  the firstling of the beasts, which firstling, no man"
Numbers 1:20: "And the children of Reuben, Israel's  eldest son, after their families, by the house of their fathers,"
Numbers 3:2: "of the sons of Aaron;  the firstborn, and Abihu, Eleazar, and Ithamar."
Numbers 3:12: "the children of Israel instead of all  the firstborn that openeth the matrix among the children"
Numbers 3:13: "Because all  the firstborn are mine; for on the day all the firstborn in the land"
Numbers 3:13: "are mine; for on the day all  the firstborn in the land of Egypt I hallowed unto me all"
Numbers 3:13: "of Egypt I hallowed unto me all  the firstborn in Israel, both man and"
Numbers 3:40: "Moses, all  the firstborn of the males of the children of Israel from a month"
Numbers 3:41: "instead of all  the firstborn among the children of Israel; and the cattle of the Levites"
Numbers 3:41: "of the Levites instead of all  the firstlings among the cattle of the children of Israel."
Numbers 3:42: "him, all  the firstborn among the children of Israel."
Numbers 3:43: "And all  the firstborn males by the number from a month old"
Numbers 3:45: "the Levites instead of  the firstborn among the children of Israel, and the cattle of the Levites"
Numbers 3:46: "And for those that are to be redeemed of the two hundred and threescore and thirteen of the firstborn  of the firstborn of Israel,"
Numbers 3:50: "Of  the firstborn of the children of Israel he the money;"