From eagle +‎ -let (diminutive suffix).

eaglet (plural eaglets)

1. The immature young of an eagle; an eagle chick.
   • 1861, Charles Boner, “The Golden Eagle”, in Forest Creatures, London: Longman, Green, Longman and Roberts, page 177:

     He [Christopher North] speaks in his "Second Canticle" of "the imps," "the eaglets," "the young ones," "the bursting of the shells," as though it were the commoner occurrence for there to be several eaglets in a nest. This is not the case.

   • 1879 January, Ellis Clare, “The Christmas Eaglet”, in Ballou's Monthly Magazine, volume 49, number 1, Boston: Thomes & Talbot:

     Alas! in the morning the eaglet was gone; and, full of sorrow, they stooped to pick up the shining fleece with which the floor was spread. At their touch, every feather became a golden coin.

   • 1900, M. Gaster, “Art. XIII.—Contributions to the History of Aḥiḳar and Nadan”, in Journal of the Royal Asiatic Society of Great Britain & Ireland, page 308:

     [A]fter the ten days Arkirie came to the king and asked him to give him two eaglets.

   • 1962 July, Richard Petrow, “Last chance to save the Bald Eagle”, in Popular Science, volume 181, number 1, →ISSN, page 192:

     Once the eaglets are born—tiny balls of white fuzz—the adult eagles prove that birds can be as protective and solicitous of their young as humans. They'll rip food into bite-size pieces for the eaglets and stand ceaseless watch over the eyrie.

   • 2024 March 6, Francine Kiefer, “Bald eagles offer webcam lessons on patience and parenting”, in The Christian Science Monitor:

     The early days and weeks of an eaglet’s life are not without risks.

• Legate, Teagle, gelate, legate, teagle, telega