Tempestuous comes from Late Latin tempestuosus, from Latin tempestas ('storm, weather, season'), from tempus ('time'). The historical chain includes Latin tempestas and Latin tempus. The quoted older senses, "storm, weather, season" and "time", supply the semantic anchors for tempestuous. The formation is best read as borrowed: the word tempestuous carries its older form-history into a compact English lexical shape. In present English it is used as a adj, "characterized by strong, turbulent emotion or weather". English derivatives include tempestuously and tempestuousness; related English forms include tempest, temporal, and tempo. The result is a adj whose etymology preserves both the older form and the later English specialization.