The Collaborative International Dictionary of English v.0.48:
Sapsago \Sap"sa*go\, n. [G. schabzieger; schaben to shave, to scrape + zieger a sort of whey.] A kind of Swiss cheese, of a greenish color, flavored with melilot. [1913 Webster]WordNet (r) 3.0 (2006):
sapsago n 1: a hard green Swiss cheese made with skim-milk curd and flavored with clover