Our research has revealed the existence of phraseological units which contain in their structure lexical units that can only be found in the language of phraseology. These lexemes that occur only in the structure of phraseological units impress by the fact that they are only present in the fixed phrases in which they appeared. They probably cannot be considered lexical units in the true sense of the word, being devoid of independent semantic content, since they only serve a "verbal segment", without claiming to "become citizens" in the language or to penetrate into general use as autonomous lexical units. They remain somewhat at the periphery of vocabulary, their resistance in time being unknown and depending directly on the degree of "vivacity" of the phraseological unit. Some of them acquire a "residence visa" in the explanatory dictionaries of the Romanian language, being considered isolated lexical units in fixed phrases, requiring a special explanation, in brackets.