D defs.my
Entry 2 senses Webster, 1913

Eldest

/ĕl'-dəst/ · Eld·est · IPA /ˈɛldɪst/
01 a. Oldest; longest in duration.
  1. 1.
    Oldest; longest in duration.
  2. 2.
    Born or living first, or before the others, as a son, daughter, brother, etc.; first in origin. See Elder. See: Elder
    “Their eldest historians are of suspected credit.” — Bp. Stillingfleet.
Phrases & compounds
Eldest hand — the player on the dealer's left hand.