Green’s Dictionary of Slang

Greek n.

[the ‘foreignness’ of Greek whether as a language or person]

1. [16C+] a cunning, sly individual, esp. a gambler or swindler [20C+ use is derog.].

2. [late 16C+] unintelligible language, esp. cant or sl.; esp. in phr. it’s all Greek to me, suggesting that something is incomprehensible; occas. of actions or ideas.

3. a genteel beggar.

4. [19C+] a derog. term for an Irish immigrant to the US or UK; cite 1880 is not derog.

5. [mid-19C] a newcomer.

6. [1930s+] (US campus, also Greek freak) a member of a college fraternity or sorority; thus as adj. [the use of Greek letters as the names of such societies].

7. [1930s+] a person who engages in anal intercourse, not necessarily but usu. a homosexual [the stereotyped identification of Greeks with homosexuality].

8. [1930s+] (also G) anal intercourse; often used on a prostitute’s ‘bill of sale’.

In phrases

go Greek (v.)

[1970s+] (US campus) to join a college fraternity or sorority.