From chat GPT:

Reticent is an adjective used to describe someone who is reserved, reluctant to speak, or not inclined to reveal their thoughts or feelings. A reticent person tends to be quiet or restrained in social situations and avoids sharing personal information or opinions unless necessary.

For example: • She was reticent about discussing her private life. • Despite his success, he remained reticent in interviews, preferring to let his work speak for itself.