Search Result for "sigma": 
Wordnet 3.0

NOUN (1)

1. the 18th letter of the Greek alphabet;


The Collaborative International Dictionary of English v.0.48:

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]
WordNet (r) 3.0 (2006):

sigma n 1: the 18th letter of the Greek alphabet
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SIGMA Software Industrialized Generator and Maintenance Aids system (MITI)
The Free On-line Dictionary of Computing (30 December 2018):

SIGMA A scientific visual programming environment from NASA. (http://fi-www.arc.nasa.gov/fia/projects/sigma/).