# Antonym of variance

Is there a word that means the 'inverse of variance'? That is, if $X$ has high variance, then $X$ has low $\dots$? Not interested in a near antonym (like 'agreement' or 'similarity') but specifically meaning $1/\sigma^2$?

• Agreement and similarity are in any case pretty much preempted, at least in formal definitions, for pairwise and other comparisons. However, that doesn't rule out informal talk, e.g. you can see from the low variance that different measurements tend to agree Nov 25, 2015 at 11:41
• I added [bayesian] tag since, as you can see from my answer and comments, the answer is closely related to Bayesian statistics and it will be easier to find tagged like this.
– Tim
Dec 2, 2015 at 8:33

$1/\sigma^2$ is called precision. You can find it often mentioned in Bayesian software manuals for BUGS and JAGS, where it is used as a parameter for normal distribution instead of variance. It became popular because gamma can be used as a conjugate prior for precision in normal distribution as noticed by Kruschke (2014) and @Scortchi.