Definition of "mooncalf"

mooncalf

/ˈmuːnkɑːf/

noun
plural mooncalves
1. (now rare) An abnormal mass within the uterus; a false conception.
  Quotations
  Thou art very Trinculo indeed! How camest thou to be the siege of this moon-calf? Can he vent Trinculos?
  1610–1611 (date written), William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene ii]
2. A poorly-conceived idea or plan.
3. A dreamer, someone absent-minded or distracted; a fool, simpleton.
  Quotations
  “ […] you’re a jobbernowl and a doodle, a maundering mooncalf and a blockheaded numps, a gaby and a loon; you’re a Hatter!” I shrieked the last epithet.
  1902, John Kendrick Bangs, chapter 10, in Olympian Nights‎, New York: Harper & Bros., page 185
  But I can think of no one but a mooncalf or a gabyWho would trust their own child to raise a baby.
  1957, Ogden Nash, “Come On In, The Senility Is Fine”, in You Can’t Get There From Here‎, Boston: Little, Brown & Co., page 66
  He slipped it softly onto her unresisting finger and, like the unwise moncalf he was, kissed it.
  1978, Lawrence Durrell, Livia (Avignon Quintet), Faber & Faber, published 1992, page 463