Unsurprisingly, there are many articles published about "The Awful English Language" , such as: [1], [2], [3] Some examples from [2]: Let's face it -- English is a crazy language. Besides the above, there is no egg in eggplant, nor ham in hamburger; neither apple nor pine in pineapple. English muffins weren't invented in England or French fries in France. Sweetmeats are candies while sweetbreads, which aren't sweet,…
If you look at an eggplant in its early stages, you will understand the name.
So nope, not "an" eggplant, some eggplants, and those only may look like eggs in their early stages. They may also look like plums. Do we call the purple eggplants plumplants because they resemble plums at some indeterminate stage in their growth?