The act of engaging in sexual contact, without actual penetration of the anus, but of still achieving orgasm.
To engage in sex, without actual penetration of the penis and the anus. To rub against another male's body, until orgasm is achieved, or ejaculation occurs.
The physical act itself predates man, as it is evident in the animal kingdom where the male species engage in this activity, however the actual term 'frot' came into existence around 2000, when coined by Bill Weintraub.
Male bonobos (pigmy chimps) (closely resembling human actions) engage in penis fencing, which is where both males rub their penises in a sort of fencing type action, which is similar to Frot in human males.
FROT is derived from the French word, frotter, meaning 'to rub'.
Frot is the practice of where two males, rub their erect penis together, simulating penetration, until ejaculation. This can be done in any position, where both penises can easily be in contact with each other, and where the motion is both sensual and pleasurable.
Standing together is one, laying on top of each other is another, though there are many different positions. One being where both are on their hands and knees, their buttocks pushed together.
Reaching beneath themselves, they push their genitals towards the other, and mutually rub the organs, until ejaculation is achieved.
The sole purpose of Frot is for both parties to rub their penises together, no matter what position is taken, until ejaculation.
Practice (Associated Acts): Frottage - This is where one person rubs their penis on another persons body, or has their penis rubbed by other body parts of their partner, other than the penis.
Use of a foot for example, that massages the penis of one's partner, is frottage, the rubbing effect being the key here.
Armpit sex is another example of frottage, NOT frot.
This is about one person achieving ejaculation, through the rubbing of the penis in other mannerisms, though technically a hand job could be considered frottage.
Frottage does not involve the use of a condom, nor does frot. It is about the creation of friction, that can be most erotic to some, as well as painful, due to the lack of lubrication.
Noteworthy: Frot and Frottage are touted for being a form of safe sex, however the risk of STI's (sexually transmitted infections) and other sexual diseases such as Herpes, Crabs, and such, are more probable when engaging in this form of sexual contact.
Mainly this is due to the lack of protection used in such practices, that being a condom.
Frotteurism - the term used to describe those who engage in rubbing or frot without the actual consent of the other partner. This is the desire to seek sexual gratification, illicitly.
It is considered a 'criminal act' in many places, and generally occurs in public locations such as on trains, buses, or in crowded auditoriums during various events.
A common term is 'groping' and victims may not even know it, or realize that the casual 'bump' was sexually motivated. It is also more common for adults to 'grope' minors, generally males to female minors.
Originally the term was 'frottage' which has been altered to 'frotteurism' with 'frottage' meaning 'consensual groping'