Kαλλικράτης = ο δούρειος ίππος της Ελλάδας = euphemism

A euphemism is a substitution with an agreeable or less offensive expression in place of one that may offend or suggest something unpleasant to the receiver,[1] or to make it less troublesome for the speaker, as in the case of doublespeak. The deployment of euphemisms is a central aspect within the public application of political correctness.

It may also substitute a description of something or someone to avoid revealing secret, holy, or sacred names to the uninitiated, or to obscure the identity of the subject of a conversation from potential eavesdroppers. Some euphemisms are intended to amuse.

for more see http://en.wikipedia.org/wiki/Euphemism