The fruit commonly known as "tamarillo" was originally called "tree tomato" but was renamed by the New Zealand Tree Tomato Promotions Council to avoid confusion with the common tomato and increase its appeal to export markets. 

Here's a more detailed explanation:

Original Name:

The fruit, native to the South American Andes, was initially known as "tree tomato" or "tomate de árbol" in Spanish. 

"Tamarillo" Origin:

The name "tamarillo" was chosen because it sounded both Spanish and Māori, and it was officially adopted on February 1, 1967. 

Other Names:

Besides "tree tomato" and "tamarillo," the fruit is also known as "tomate de árbol" (Spanish), "tomate de arvore" (Portuguese), and "sachatomate" (Peruvian). 

Culinary Uses:

Tamarillos are used in a variety of ways, including eaten fresh, used in chutneys, sauces, desserts, and juices.