In the context of
human sexual behavior,
frottage or
frotteurism is the act of obtaining sexual gratification by rubbing
one's (
clothed or
naked) body against another person.
Frottage carries a connotation of 'anonymous and discreet rubbing' in a
public place - like on a crowded
train. The contact may be mutual or a one-way exchange. A person who practices frotteurism is known as a
frotteur.
As with most other sexual practices, frottage with a non-consenting person is regarded as a form of sexual assault in most jurisdictions.