expression, noun-modifying (irregular)
sincere; faithful; substantial
Describes a person, action, or statement that is genuine, heartfelt, and not superficial. Often used in phrases like 実のある話 (a sincere/substantial talk) or 実のある人 (a sincere person).
彼はいつも実のあるアドバイスをくれる。
He always gives me sincere advice.
会議では実のある議論ができた。
We had a substantive discussion at the meeting.
誠実 is a noun/adjective meaning 'sincere' or 'faithful' as a character trait, while 実のある is a phrase used attributively to describe something as having substance or sincerity.
中身のある also means 'substantial' or 'having content,' but is more concrete (e.g., a gift with real contents) or can refer to a person's depth, whereas 実のある leans toward sincerity and genuineness.
Phrase composed of 実 (truth, substance) + の (possessive particle) + ある (to exist). Literally 'having substance/truth.'