Maxim

The name is a shorter form of Maximus, after St. Maximus the Confessor, an Eastern Roman (or "Byzantine") theologian, diplomat and scholar born in Constantinopolis (now Istanbul) in 6th century. French and most of southern and eastern Europeans use Maxim(e) as the name form. Orthodox church celebrates St. Maximus on January 21 (Julian calendar) and Catholic on August 13 (Gregorian calendar).
https://en.wikipedia.org/wiki/Maximus_the_Confessor.

Alternatively the name comes from Hebrew מַקסִים, which means charming or, literally "one, who casts magic on others".