Psychoanalysis, as an archaeology of the unconscious, sometimes becomes an archaeology of the language itself. What does the signifier mean? The answer to such a question can require a lexicographic and an etymological research. Freud does one on Unheimlich and then suggests an almost Cratylian interpretation of the term, by considering the prefix un- as the trace left by the unconscious. The translation of such processes is highly problematic. The translators of the Oeuvres complètes Psychanalyse (Presses Universitaires de France) claim to be source-oriented translators, meaning that the respect of the letter of the original text is essential. In such a perspective, the signifier contains latent significations which have been forgotten by the usage and could be compared to a semantic unconscious: translation is 'anasémie', potential significations literally 'come up.' The target-oriented translation and the psychoanalytic method seem to have a lot in common: in the Freudian theory, the analyst is a translator.