Definition of "moonstruck"

moonstruck

adjective
comparative more moonstruck, superlative most moonstruck
1. (obsolete) Crazy or insane when affected by the phases of the Moon.
  Quotations
  And moon-struck madness, pining atrophy
  1667, John Milton, “Book XI”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873,
2. (by extension) Showing irrational behaviour, especially of a romantic or sentimental nature.
  Quotations
  [W]e can also overlook the verbiage of a good deal of the mind-cure literature, some of which is so moonstruck with optimism and so vaguely expressed that an academically trained intellect finds it almost impossible to read it at all.
  1902, William James, The Varieties of Religious Experience, Lectures 4 & 5
  The full moon was spacious now behind the maples. The seedy Pickerbaugh domain was enchanted […] and over all the world was the proper witchery of moonstruck love.
  1925, Sinclair Lewis, “21, IV”, in Arrowsmith
3. (obsolete) Made sick, or (like fishes) unsuitable for food, by the supposed influence of the Moon.