誠

1. Origins, structure, and basic meaning

• Structure: 誠, read まこと, is a single noun written for sincerity and integrity without falsehood.
• Basic usage: It is a literary way to express wholehearted sincerity, as in 誠を尽くす.

2. Common pitfalls and similar expressions

• Tone and register
  • As a noun it emphasizes the virtue of sincerity more than the everyday adjectival expression 誠実な.