Forte | Mezzo
It does not represent a specific decibel level. A mezzo forte played by a full orchestra will be much louder than a mezzo forte played by a solo flute.
π΅ If you're comfortable sharing, tell me (e.g., for music theory homework, learning an instrument, or analyzing a score) so I can give you more tailored information. Mezzo Forte
It is typically placed below the staff for instruments and above the staff for vocal parts. It does not represent a specific decibel level
