Daisy has changed a lot over time, but its original pronunciation was by far the best. In literature, daisy has been corrupted a tremendous amount. In Modern English, it also used to be spelled daisie and daysie. Going backwards, the latter is perhaps more appropriate, because in Middle English, daisy was spelled several ways, including daysie, daieseyghe, and dayseye. The reason this changed so much over time is because nobody could agree on the proper spelling. However, when traced further back to Old English, the spelling was uniform (daeges eage), mainly because there weren't many people writing back then. You may have noticed a pattern to the pronunciations by now: they all sound like day's eye. In fact, that is what it used to be! Daisy, though it's hard to guess now, is a combination of the Old English words daeges, "day's", and eage, "eye". It was named thus because the petals open at dawn and close at dusk (similarly, in Latin it was solis oculus, or "sun's eye"; this likely had an influence on daeges eage). Daisy as a woman's name was apparently a nickname for Margaret (and today is as appropriate as Peggy).
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.