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:
1 Chronicles 26:2: "And the sons of Meshelemiah were, Zechariah  the firstborn, the second, Zebadiah the third,"
1 Chronicles 26:4: "Moreover the sons of Obed-edom were, Shemaiah  the firstborn, the second, Joah the third,"
1 Chronicles 26:10: "(for though he was not  the firstborn, yet his father made him the chief;)"
2 Chronicles 21:3: "he to Jehoram; because he  was the firstborn."
Nehemiah 10:36: " Also the firstborn of our sons, and of our cattle, as it is written and the firstlings of our herds and of our flocks,"
Job 1:13: "and drinking wine  in their eldest brother's house:"
Job 1:18: "were eating and drinking wine  in their eldest brother's house:"
Job 18:13: "It shall devour the strength of his skin:  even the firstborn shall devour his strength."
Psalms 78:51: "And smote all  the firstborn in Egypt; of their strength in the tabernacles of Ham:"
Psalms 89:27: "Also I will make  him my firstborn, than the kings of the earth."
Psalms 105:36: "He smote also all  the firstborn in their land, of all their strength."
Psalms 135:8: "Who smote  the firstborn of Egypt, both of man beast."
Psalms 136:10: "To him that smote Egypt  in their firstborn: for endureth forever:"
Isaiah 14:30: " And the firstborn of the poor shall feed, and the needy in safety: and I will kill thy root"
Jeremiah 31:9: "a father to Israel, and Ephraim  is my firstborn."
Micah 6:7: "of rivers of oil? shall I give  my firstborn for my transgression, the fruit of my body for the sin"
Zechariah 12:10: "for him, as one that is in bitterness for  his firstborn."