\First"ling\, n. [First + -ling.]
1. The first produce or offspring; -- said of animals,
   especially domestic animals; as, the firstlings of his
   flock. --Milton.
2. The thing first thought or done.
         The very firstlings of my heart shall be The
         firstlings of my hand.                --Shak.

\First"ling\, a.
Firstborn.
      All the firstling males.                 --Deut. xv.
                                               19.