D defs.my
Entry 1 sense Webster, 1913

Daydream

/(-drēm`)/ · Day·dream · IPA /ˈdeɪdɹiːm/
01 n. A vain fancy speculation; a reverie; a castle in the air; unfounded hope.
  1. 1.
    A vain fancy speculation; a reverie; a castle in the air; unfounded hope.
    “Mrs. Lambert's little daydream was over.” Thackeray.