[MagicPropmaker]

It means "In the beginning" (בראשית)

(The prefix "ב" meaning "in", the root "ראש" meaning "head" --used both for the part of the body, and to mean "starting" or "principal"--and the suffux "ית" being the a type of feminine suffix)

[geofft]

That said, it is the Hebrew name of the book of scripture commonly called "Genesis" in English, because it's the first word (incipit) of that book. So people who translate it as "genesis" are not totally making it up, and arguably it's a more poetic translation since the name of the book is (presumably) why they chose that name for the craft.