noun: (organic chemistry, automotive) Abbreviation of methylcyclopentadienyl manganese tricarbonyl: an octane number boosting additive to unleaded gasoline to replace TEL as an anti-knock component [(organic chemistry, automotive) (CH₃C₅H₄)Mn(CO)₃ ; an octane number boosting additive to unleaded gasoline to replace tetra-ethyl lead as an anti-knock component]
noun: Initialism of million metric ton(s).
noun: (economics) Abbreviation of Modern Monetary Theory. [A heterodox economic school of thought that posits that fiscal policy, set to constrain inflation and enable full employment, should be the primary economic stabiliser and prioritises reflection on the nature of money from a chartalist perspective.]