What is another word for initialism?
Pronunciation: [ɪnˈɪʃə͡lˌɪzəm] (IPA) 
The term initialism refers to an acronym formed from the first letter of each word in a phrase, such as NASA or FBI. However, there are several other synonyms that can be used to refer to such acronyms. For instance, the term acronym is frequently used to mean initialism, though it technically refers to any abbreviation formed from the first letters of a phrase. The terms abbreviation and shorthand are also commonly used to describe acronyms, along with the more specialized term sigillography, which refers specifically to the study of seals and logos. Other synonyms for initialism include acronymic abbreviation, initial-letter abbreviation, and alphabetism, which is used primarily in British English.
