Short and uneven fingernails that typically go unpainted, although chipped and/or sloppy polish is not uncommon. Associated with but not exclusive to lesbians.
Straight male: Shit, I didn't notice Amy's dyke nails. No wonder she rejected me. T_T
Lesbian: Omg, Amy has dyke nails, maybe she'll go out with me! ^_^
Amy's straight friend: Amy, we need to do something about those dyke nails. They're going to give people the wrong impression...-_-