It is a chemical, most known by the name Mephedrone.
But the 2 names for it is - 4-mmc, and Mephedrone.
Its full name is - 4-methyl-N-methylcathinone; 2-methylamino-1-p-tolylpropan-1-one
or
4-methylmethcathinone
Chemical cas number is - 1189805-46-6
1189726-22-4 (HCl)
Hope this helps