Definition of "spoony"

"My dear Guy, the fact is, that I can't—force the girl's—feelings. You shall come with us—to-morrow, and speak to her as you like—but—if she does not like you—au'd'ammee! Why you know I can't make her. She—silly child—is spoony, I think, on that cousin of her's, Dalrymple—he, I believe, is spoony on her."

1852, Henry Drummond Wolff, Blondelle, page 139

Of course, it was unlikely to unfold on its own. Romilda was shy and Mr. Reeves was a professional. Even if they were absolutely spoony for each other it was difficult to imagine either of them taking that first scary step toward romance.

2020, Lorna Locke, Romie's Fantasies (Lakeside Lovers; 3)

That is why we decline to publish any of the letters and verses which Mr. Pen wrote at this period of his life, out of mere regard for the young fellow’s character. They are too spooney and wild.

1848 November – 1850 December, William Makepeace Thackeray, chapter 12, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

Major Pendennis, when the offer of the commission was acknowledged and refused, wrote back a curt and somewhat angry letter to the widow, and thought his nephew was rather a spooney.

1848 November – 1850 December, William Makepeace Thackeray, chapter 3, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

Occasionally, a Fascinating Lady catches a rich spoony whom she can manage and control. In that case, she continues to have all her whims fully gratified until Mr. Spoony's fortune is exhausted, and the creditors carry off the off the nice furniture.

1861, Marie Louise Hankins, “The Fascinating Lady”, in Women of New York, page 129