The story
From egg + plant, originally applied only to the white-colored, egg-shaped variety. Compare Dutch and Afrikaans eierplant (“eggplant”), German Eierpflanze (“eggplant”), Swedish äggplanta (“eggplant”). Compare also Afrikaans eiervrug (“eggplant”, literally “egg-fruit”), Icelandic eggaldin (“eggplant”, literally “egg-fruit”).
Etymology from Wiktionary, CC BY-SA 4.0.