Firstborn

['fɜːstbɔːn] or ['fɝstbɔrn]

(noun.) the offspring who came first in the order of birth.

(adj.) first in order of birth; 'the firstborn child' .

Checked by Abby--From WordNet

(a.) First brought forth; first in the order of nativity; eldest; hence, most excellent; most distinguished or exalted.

Editor: Maggie