The name Mona is a girl's name of Irish origin meaning "noble good". Mona and is often added to lists like Film Noir Baby Names and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
Mona had more than a moment in the sun, peaking in 1950 at Number 230 but falling off the Top 1000 completely in the late 1980s. Its similarity to the word "moaner" undercuts the appeal of its simplicity. In one recent year, fewer than 100 baby girls received the name, and we don't see it reviving any time soon.