レターretaa

1. nounletter

• Synonym書簡しょかんWrittenWritten word for correspondence, often letters exchanged by notable figures, as in 「書簡集」; 「レター」 is mostly a loanword compound element, as in 「ラブレター」.
• Synonym手紙てがみNeutralThe everyday, most common word for a letter, including short notes; 「レター」 is rarely used alone in daily speech, appearing mostly in compounds like 「ラブレター」.
• Synonym書状しょじょうWrittenWritten and old-fashioned, leaning toward formal documents and official letters; everyday letters are 「手紙」, never this.
• Synonym文ふみWrittenOld-fashioned, elegant word for a letter, as in 「恋文」; also means books, writings and learning. Everyday letters are not called 「ふみ」.
• Synonym信書しんしょWrittenWritten, legal term for letters or documents addressed to a specific party, as in 「信書の秘密」; not used in everyday speech.
• Synonym書信しょしんWrittenWritten word for letters as documents, used very little; everyday speech says 「手紙」, and it is stiffer and more old-fashioned than 「レター」.
• Related便りたよりNeutralNative word for mail one receives, also news or tidings, with a warm feel, as in 「お便り」; 「レター」 has no news sense.
• Related書札しょさつWrittenLetters, also documents and written notes; archaic written word almost never heard today — say 「手紙」 instead.

For everyday letters say 「手紙」; 「レター」 itself mostly appears in compounds like 「ラブレター」 and 「ニュースレター」. Use 「書簡」 for notable figures' correspondence, 「信書」 in legal contexts, 「便り」 for mail or news received; 「書状」「書信」「書札」「文」 are archaic written words.

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

1. 手紙てがみ、書簡しょかん、書状しょじょう。
2. 文字もじ、アルファベット。
3. 活字かつじ。
4. 公式こうしき文書ぶんしょ、認可状にんかじょう。