[ 'frɒtα:ʒ ]
■ noun
1》 the practice of rubbing against the clothed body of another person in a crowd as a means of obtaining sexual gratification.
2》 Art the technique or process of taking a rubbing from an uneven surface to form the basis of a work of art.
Origin
1930s: Fr., 'rubbing, friction', from frotter 'to rub', of unknown origin.