riss glaciation is a noun meaning "the next-to-last Pleistocene glaciation in the Alps and the deposits laid down at that time". It carries one recorded sense.
the next-to-last Pleistocene glaciation in the Alps and the deposits laid down at that time
Definitions, synonyms and semantic relations for riss glaciation come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.