acronym; initialism
Refers to a word formed from the initial letters or parts of a phrase, such as NATO or FAQ. In Japanese, often used for both acronyms and initialisms.
"NATO" is an example of an acronym.
この用語集では、よく使われる頭字語をまとめています。
This glossary compiles commonly used acronyms.
頭字語 refers to the whole acronym formed from initial letters, whereas 頭文字 refers to a single first letter itself.
recursive acronym
Compound of 頭 (initial, head) + 字 (character, letter) + 語 (word). The exact historical derivation is uncertain, but the term is a modern coinage for 'acronym'.