Slang for the buttocks, 19-20 century. In 17th-18th century jere was slang for turd.

The Routledge dictionary of historical slang by Eric Partridge, 1973

According to the entry on slang in the Encyclopedia of homosexuality almost all terms for gay men fall into four categories: 1. those who take an active 'masculine' role - the insertor role in anal inercourse; 2. the 'passive', 'feminine' role, the receptor; 3. effeminate men who may be gay; 4. the category of the fellator.

Many slang terms for the 'passive homosexual' directly personify him as a vagina or as an anus.

"Slang" in the Encyclopedia of Homosexuality Ed. by Wayne R. Dynes