frotteurn.

1892 C. G. Chaddock tr. R. von Krafft-Ebing Psychopathia Sexualis v. 496 A forensically important variety of exhibition..which expresses itself in a peculiar act, conditioned by violent libido (hyper aesthesia sexualis), associated with diminished virility, is made up of the so-called frotteurs.

1928 J. Bloch Sexual Life of our Time xxiii. 652 As a sub-variety of exhibitionists, we must refer to the so-called ‘frotteurs’, individuals who rub their genital organs, either bared or covered, against persons of the opposite sex.

1950 London & Caprio Sexual Deviations vii. 361 In frottage the orgasm is generally induced when the frotteur rubs or touches the woman's gluteal region.

1961 Ellis & Abarbanel Encycl. Sexual Behavior 807/2 Frotteurs are only truly perverted when they avoid coitus and other sex acts.

1984 ‘Tiresias’ Notes from Overground 159 Train..nullifies significance and sanctity of physical contact. Thigh pressed to thigh, knee to knee, pretty girl's sleepy head on strange man's shoulder—all mean nothing except to a dedicated frotteur.

1954 G. I. M. Swyer Reproduction & Sex 260 Frotteurism, a perversion in which sexual pleasure is obtained by contact with other persons.

1989 Time Out 10 May 14/2 Frotteurism on the Underground is in—the Circle line is best, you can stay there all day for 60p, but Thursday afternoons on the Docklands Light Railway is strongly recommended.