マイペース、マイ・スタイル！　～日本語がぺらぺらになるには～

Acronym is a fairly recent word, dating from the 1940s, although acronyms existed long before we gave them that name. The term was preceded in English by the word initialism, meaning an abbreviation formed from the initial letters of a phrase, and which has been in use since the late 19th century.

Some people feel strongly that acronym should only be used for terms like NATO, which is pronounced as a single word, and that initialism should be used if the individual letters are all pronounced distinctly, as with FBI. Our research shows that acronym is commonly used to refer to both types of abbreviations.

initialism is 頭文字語　かしらもじご

acronym is 頭字語◆ とうじご
例えば、North Atlantic Treaty Organization＝NATO（ネイトー）のように、頭文字を並べたものが一つの単語として発音可能なもの。◆【参考】initialism

... but, in Japanese, acronyms can also be called 頭文字語　かしらもじごabbreviation, which can be a shortened word (i.e. split in half, like "gov." for "government") or an initialism

abbreviation=
略語、略称◆可算
・What's the abbreviation for 'Wednesday'? : Wednesdayの省略形は何ですか。

電子メールでよく使われる略語

amino-acid abbreviation   アミノ酸略号［略語］

トリプトファン	Tryptophan	Trp	W

currency abbreviation  通貨略称
USD for US Dollar

JPY for Japanese Yen

medical abbreviation  医学用略語