Mundhir
Yes. Mundhir is recorded in Arab histories and genealogies; several rulers and tribal leaders were known by this name or epithet.
The name carries moral and social connotations related to warning and admonition. The concept of warning appears throughout Islamic scripture, but 'Mundhir' itself is not a Quranic proper name.
In Arabic the common pronunciation is /mun.dhir/ with a voiced dental fricative; in many non-Arabic contexts it is approximated as MUN-dhir or MUN-deer.
No. Mundhir is relatively rare in modern usage, though it is retained in families valuing classical or historical Arab names.
Yes; medieval Arabic histories record leaders and kings bearing the name al-Mundhir, particularly among pre-Islamic Lakhmid dynasts and early Arab nobility.