From the surname Monroe.
Used as a feminine name too.
Meaning “mouth of the Roe”.
The Roe is a river in Ireland. The origin of the name “Roe” is not clear. Sources mention a Viking origin and the Irish word “rua”, meaning “red”.
Famous male bearers are: Monroe Robertson, Monroe Salisbury, Monroe Owsley.
After Mariah Carey and Nick Cannon named their daughter Monroe, honoring Marilyn Monroe, the name made a comeback as a feminine name.