The discrimination we face as same-sex couples is based on sex, not gender. The terms are not interchangeable. Sex identifies the biological make up and difference between the male and the female. Gender is constructed socially and identifies the relationship between men and women. To put it another way: gender is the role played, sex is the plumbing.

The law currently denies marriage to two women or two men because of the physical bodies they inhabit, not because of the sex role(s) they play, whether “feminine,” “masculine” or otherwise. Likewise, a man who assumes a female gender by dressing and acting “like a woman” can still marry a woman.

Some may have favored the term “same-gender” under the assumption that “gender” is more palatable than “sex.” However, an unpublished survey of voters conducted in 1997 tested the use of “gender” and “sex” to learn which term resulted in more support of marriage for gay men and lesbians. “Gender” gained us only three percentage points — not enough to prefer the term, particularly as it confuses the issue.

Many people support the idea of marriage. Those who don’t seem less concerned with the language. They either don’t understand the issue as one of equality, don’t think marriage is a good idea for anyone, or simply dislike gay men and lesbians.

Like many words, “sex” has multiple meanings. Because “sex” can refer to intimate behavior, some prefer to avoid the word “same-sex” for fear of misunderstanding. However, doing so sacrifices the clarity of understanding that the sex status of gay men and lesbians is fundamental to the marriage discrimination we experience.

The term “same-sex marriage” makes crystal clear what’s at stake. It’s not about having sex, it’s about marrying someone of the same sex. Stealthy language will never succeed in slipping this issue through a legislature, voters, or the courts. Heartfelt, well reasoned appeals stand a far greater chance of success.

Let us also put to rest the term “gay marriage.” Opposite-sex couples do not describe their relationships as “straight marriage.” Using the term “gay marriage” only gives the impression that we are asking for something different or “special,” whereas our only demand is for the same treatment opposite-sex couples receive.

We are not denied marriage because of our sexual orientation. In fact, there are plenty of married gay men and lesbians — they happen to be married to opposite-sex partners. These gay men and lesbians were able to marry because their partners had different anatomy. No marriage license asks for the sexual orientation of marriage partners.

This concern for preciseness of language in the campaign for same-sex marriage does not arise from an interest in “political correctness,” but from the knowledge that language defines the dream — and the dream defines the future.