Definitionirrumatio. Etymology: From the Latin irrumare , suck or fellate.
1. Masturbation or copulation between the thighs of another man or, less often, between the two mens abdomens.
SYNONYMS: coitus ante portas; coitus inter femora; coitus interfemoris; college fuck; college style; dry fuck; dry hump; dry run; English method; femoral intercourse; Harvard style; interfemoral intercourse; intracrural intercourse; irrumatio(n); leg work; leggins; Princeton Rub or style; rubbins; slick leggins; thigh sandwich; thighs.
2. Fellatio by actively thrusting the penis into the mouth of a partner. A distinction was once made between fellatio and irrumatio based on who is actively moving: irrumatio meant to thrust the penis into the partner's mouth, fellatio meant to move the head and mouth up and down around the penis; this distinction has almost completely vanished in modern English and the word irrumation has fallen out of use.