A derogatory term for an openly homosexual man or woman who is either against equal treatment under the law for the gays, lesbians, bisexuals, or transpeople, or believes that they are inferior to heterosexuals.
The term derives from "Uncle Tom", which has a similar description for African Americans.
Someone who seeks to mask their discriminatory words and actions with regard to homosexuality beneath a veil of high minded moral disapproval. Someone who believes heterosexual couples are superior to homosexual couples, and therefore deserve respect and rights that are not afforded to heterosexuals.
Person 1: Can you believe that guy? What a homophobe!
Person 2: No, no! He's a 'heteroseparatist'.
Person 1: Oh, so he's like a homophobe, but with less integrity and honesty?
Person 2: Yep.