Noun
semivariogram (plural semivariograms)
(statistics) A function of the spatial dependence of semivariance; a graph of this function.
However, Bachmaier and Backes (2008), who discussed this confusion, have shown that should be called a variogram, terms like semivariogram or semivariance should be avoided. Source: Internet
Many authors call a variogram, others use the terms variogram and semivariogram synonymously. Source: Internet