Mammoth Uncensored Word List:
24 - 14 letter words starting with my

mycofiltration mycotoxicology mycotoxologies myelencephalic myelencephalon mylonitisation mylonitization myocardiograph myocardiopathy myographically myrmecochories myrmecological myrmecologists myrmecophagous myrmecophilies myrmecophilous myrmecophobics mystagogically mysteriousness mysticalnesses mystifications mythicisations mythicizations mythologically