Menacing in the 1st Degree means the police allege that you have committed menacing again, after you have previously been convicted of menacing. This new charge is then elevated to a felony based on your prior conviction.
Menacing in the 1st Degree is a class E felony under NY Penal Law §120.13. This means you face a maximum of 4 years in New York State prison and/or up to 5 years of probation.