What is the word for words that begin and end with same letter?

There isn't a single, universally accepted word for words that begin and end with the same letter. However, there are a few options you could use:

* Alliteration: This term usually refers to words starting with the same sound, but it can also be applied to words with the same beginning and ending letter.

* Repetition: This is a more general term that encompasses any repetition of sounds or letters within a word or phrase.

* Words with initial and final letter symmetry: This is a more technical and descriptive phrase that accurately describes the characteristic.

* "Words that start and end with the same letter": This is the most straightforward and understandable option.

Ultimately, the best term to use will depend on the context and your intended audience.