Phraseology, as an important language compartment, has a dynamic character. The dyna-mics of phraseology is manifested by the increasing number of phraseological units and by their modifi-cation, as well as by a very productive phenomenon of phraseological variation, "phraseological derail-ment", which is a type of reorganization (by de-structuring / re-structuring the signifier and the signified of the phraseological unit) that occurs spontaneously or with a stylistic intent. "Phraseological derailment", the emergence of phraseological duplicates, whether ephemeral or occasional, is a testimony to the fact that phraseological units are dynamic models. The perpetual competition between canonical forms alias traditional ones as well as between various duplicates and innovative variants catalyses multiple changes in expression and content. The article focuses on the dynamics of phraseological units with archaic elements in modern Romanian from the perspective of the phenomenon of "phraseological derailment" and related phenomena, highlighting, as much as possible, a series of changes of form and meaning of some phraseological models consecrated by use as canonical and traceable forms in Romanian dictionaries.