‖n. pl. [ L. ] The signs, abbreviations, letters, or characters standing for words, shorthand, etc., in ancient manuscripts, or on coins, medals, etc. W. Savage. [ 1913 Webster ]
‖n.; pl.Sigmas [ L., from Gr. &unr_;&unr_;&unr_;, &unr_;&unr_;&unr_;. ] The Greek letter Σ, σ, or ς (English S, or s). It originally had the form of the English C. [ 1913 Webster ]