• Chambers's Twentieth Century Dictionary
    • n Sap-roller sap′-rōl′ėr a gabion employed by sappers in the trenches.
    • ***


In literature:

However, in order to push forward the siege-works, sap-rollers had to be brought into use.
"The Franco-German War of 1870-71" by Count Helmuth, von Moltke
At the mill the canes are run between heavy rollers, which squeeze out the sap.
"How We are Fed" by James Franklin Chamberlain