Rare specialist use, from German Riss. In ordinary modern Japanese, 骨折 is the usual word for a bone fracture.
from German Riss
Rare art or catalog term for a lithograph; リトグラフ or 石版画 is clearer in ordinary explanation.
In specialist terminology, the German-derived term リス can refer to a fracture.
In print catalogs, リス can refer to a lithograph.
栗鼠 (also written リス) means 'squirrel' and is completely unrelated to the rare specialist word リス meaning 'fracture' or 'lithograph', despite sharing the same reading and often the same katakana spelling.
counter for small animals · counter for rolls of cloth · archaic counter for horses · roll of cloth
The fracture sense is marked as a borrowing from German Riss. No origin of the lithograph sense is specified, so its derivation should be treated as uncertain.