What is name for word made up of initials only?

There isn't one specific, widely-accepted term for a word made up of initials only. However, here are some terms that can be used:

* Acronym: This is the most common term used for words formed from the initial letters of a phrase, even if they are pronounced as a word (like NATO or NASA).

* Initialism: This term is used when the initials are pronounced individually (like FBI or USA).

* Abbreviation: This is a broader term that encompasses acronyms, initialisms, and other shortened forms of words or phrases.

Ultimately, the best term to use depends on the specific context and the desired level of formality.