RissPronunciation: /rɪs/Definition of Riss noun [usually as modifier] Geology the penultimate Pleistocene glaciation in the Alps, possibly corresponding to the Saale of northern Europe. the system of deposits laid down during the Riss glaciation. Origin: early 20th century: from the name of a tributary of the River Danube in GermanyRiss in other Oxford dictionaries Definition of Riss in the US English dictionary
