Syncretism

The stable combination within one form of several meanings or meaning components that are distributed across different forms in cases correlated with the given one, or at earlier stages in the history of the language.

Syncretic forms may be interpreted as polysemous (polyfunctional) or homonymous. Syncretism can also refer to the cumulation of grammatical meanings — the expression of several grammemes from different grammatical categories by a single indivisible marker (for example, in Russian zima, the ending -a cumulatively expresses nominative case and singular number).