podle http://dictionary.reference.com/search?q=penetration&r=67
se ted bavime o vyznamu podle 4a (The degree to which a commodity, for example, is sold or recognized in a particular market) a ne podle 1c (Insertion of the penis into the vagina or anus).!
i kdyz podle 1c bych to neomezoval jenom na pracovnice.. vsimnete si toho 'anus' :)))