1) among the Greeks an earthen jar, into which wine was drawn off for keeping but also used for other purposes
1a) of the little jar in which the manna was kept, laid up in the ark of the covenant
Part of Speech: noun feminine
From the base of G2476 (as stationary); a jar or earthen tank: - pot.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root στάμνος; click on the second column to search for that grammatical form of the root στάμνος; click on the third column to search for that word and grammatical form; click on the total to search for the root στάμνος.