Where does “مایخوش” come from?

مایخوش (Persian) comes from Persian مایه, from Middle Persian mʾtk' — essence, substance.

Ancestry of “مایخوش”, step by step

Step	Language	Word	Meaning
1	Persian	مایه	stuff, matter, substance, essence; leaven, yeast,...
2	Middle Persian	mʾtk'	essence, substance

مایخوش — Etymology, Origin & Word History | Etymology Explorer