Worsening comes from worsen + -ing, from worse, from Old English wiersa ('worse'), a comparative formed from a Proto-Germanic root meaning 'to confuse, mix up'. In current use it is a noun and adjective meaning "the process of becoming worse; deterioration". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The -ing ending supplies a participial or action-noun shape. The surface form is compositional: its joined elements remain visible in the modern word. The historical chain includes Old English wiersa and Proto-Germanic *werz-. Related English forms include worsen, worse, and worst. The word's history is thus visible in its construction: the components remain interpretable even after the whole expression has settled into a conventional English meaning.