The article attempts to address the problem of polysemy via metaphor, since metaphor is one of the constitutive conditions for the existence of language, the most important way of describ-ing objects of a high degree of abstraction. Mechanisms that provide quick access to lexemes with-out the need to scan lists of meanings are presented, the mechanisms of functioning of metaphorical meanings are described. It is suggested that the use of the core of meaning that stands for the entire structure of a polysemantic word allows in the process of communication to carry out an effective search and to fit metaphorical meanings into the context of utterances. A lexical invariant acts as a general cognitive model of perception and understanding of the world, and at the neurobiological level it leads to the build-up of new neural connections. Such formations play the role of effective substitutes, dispensing consciousness with the necessity of scanning the entire spectrum of meta-phorical meanings, supporting the principle of linguistic economy therewith.