verb
To rub, especially to rub onto one surface placed upon another surface that is textured, in order to create a mottled or patterned area on the first surface.
(sexuality) To rub parts of the body against those of another person for sexual stimulation.
noun
(uncountable, art) A method of making an image by placing a piece of paper against an object and then rubbing over it, usually with a pencil or charcoal.
(countable, art) An illustration made by means of frottage.
(uncountable, sexuality) The practice of rubbing parts of the body against those of another person for sexual stimulation.