The lexical meaning of the word-group may be defined as the combined lexical meaning of the component members. But the term combined lexical meaning doesn’t imply that the meaning of a word-group is always a simple additive result of all the lexical meanings of the component words. As a rule, the meanings of the component words are mutually dependent and the meaning of the word-group naturally predominance of the lexical meaning of the components. The interdependence is well-seen in word-groups made up of polysemantic words. In the phrases “the blind man” and “the blind type” the words blind have different meanings.
Word-groups may be called lexically motivated if the combined lexical meaning of the group is deducible from the meaning of the components. All types of phrases are completely motivated. Non-motivated word-groups are called phraseological units, or idioms.
Criteria of stability and lack of motivation (idiomaticity). Phraseological units are defined as non-motivated word-groups that can not be freely made up in speech but are reproduced as ready-made units. The other essential feature of phraseological units is stability of the lexical components and grammatical structure.
General class-ion of phras. units was suggested by academician Vinogradov mainly according to the degree of idiomaticity:
Phraseological fusions (сращения). Completely non-motivated word-groups. The meaning of the components has no connection with the meaning of the whole group. Idiomaticallycombined with complete stability of the lexical components and the grammatical structure of the fusion. E.g. to kick the bucket (умереть), to seeze an elephant (узнать жизнь).
Phraseological unities. Practically non-motivated word-groups as their meaning can be understood through the metaphoric meaning of the whole phraseological unit. E.g. to skate on thin ice (рисковать), as busy as a bee. They are marked by a comparatively high degree of stability of the lexical components and grammatical structure.
Phraseological collocations (словосочетания). Are (partially) motivated but they are made up of words having special lexical valency, which is marked by a certain degree of stability. They differ from the phraseological unities by the fact that one of the components is used in its direct meaning, the other in indirect meaning and the meaning of the whole group dominates on the meaning of its components. E.g. to pay a visit, to pay attention, to break a rule, to break a silence, to meet demands.