Found 2 items, similar to Sigma.
English → English (WordNet) Definition: sigma sigma n : the 18th letter of the Greek alphabet
English → English (gcide) Definition: Sigma Sigma \Sig"ma\, n.; pl. Sigmas. [L., from Gr. ???, ???.] The Greek letter [Sigma], [sigma], or [sigmat] (English S, or s). It originally had the form of the English C. [1913 Webster]