Ein

Ein or EIN can have different meanings:

Employer Identification Number - a number assigned by the United States Internal Revenue Service to all employers. 

Ein means "a" or "one (of something)" in some Germanic languages for nouns with masculine or neuter grammatical gender in the nominative case. The feminine form is "eine". Example: in German "" is "A dog" ("" is "an ash" (the tree)). Not to be confused with "," which means "(the number) one". 

Ein also means "a" and "one" in Faroese in the male and female grammatical genders but not in the neuter. Example "".

Ein is a character in the Anime-series Cowboy Bebop.
 Ein is a character in the Anime series Phantom: Requiem from the Phantom