Ersatz French word (derived from the verb frotter, to rub) used by many sexologists to refer to any sort of sexual or erotic rubbing.
Among gay-identified men, however, "frottage" most often refers to penile-penile sex.
Because of the ambiguity in the way the word "frottage" is defined and used by different groups, and for other reasons discussed below, in the year 2000 Frot activist Bill Weintraub coined the term Frot to refer specifically to phallus-on-phallus sex.
Since then, the word "Frot" has become widely used among men who have sex with men to refer to what is colloquially known as cocktocock, dick2dick, cockrub, frontism, and bone on bone.
Please see entry for Frot.