How to say "initials" in Japanese

• イニシャル
  nounA loanword covering one's initials and, more broadly, the first letter of a name, sentence, or the like. Less common than 頭文字; a typical context is discussing the first letter of a sentence.
  イニシャルをサインしてご返送へんそうください。↗

  Please initial and send back to us.
• 頭文字かしらもじCommon
  nounThe common word for the initials of one's name, as when someone is known simply by their initials. When you mean the first letter of a sentence or the like, イニシャル covers that sense.
  「あなたはたしか・・・えーと、えーと・・・も」「頭文字かしらもじから間違まちがっとるわい！！」↗

  "Let's see, you're ... er, um ... M-" "You're wrong from the first letter!!"

For the initials of a person's name, the common word is 頭文字; 「イニシャル」, the loanword, also means one's initials and extends to the first letter of a name, sentence, or the like, but is less common.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• イニシャル(one's) initials
• 頭文字かしらもじinitials (of one's name)