firstborn
1. [ adjective ] first in order of birth
Synonyms: eldest
Examples:

"the firstborn child"

Related terms: first
2. [ noun ] the offspring who came first in the order of birth
Synonyms: eldest
Related terms: offspring
Similar spelling:   firestone
  first_moment
  first_floor
  firsthand
  firestorm
  first-string
  first_cousin
  first-rate
  first_step
  first_name
  Firestine
  firstly
  first-year
  first-rater
  First_State
  First_Reich
  first_grade
  first_gear