nalra'a lujvo

x1 is irrelevant/unrelated to x2; x1 is arbitrary in relation to x2 [object of comparison; context or referent].

Also 'random' in the sense of something that is unexpected in a particular context. Does not mean 'random' in the sense of patternless or unpredictable (the primary sense of cunso). If x1 is an utterance or sign, nalra'a does NOT mean that it is entirely meaningless (smucau), but that it does not provide any outward indication of what thing it signifies if its meaning is not already known. See also srana, sinxa, smuni, ckini, mifra, ckaji. Derivative words include nalra'aselkai 'arbitrariness', nalra'acme 'arbitrary name', sranycme 'nonarbitrary name', smura'asni 'sign whose form is related to or indicates its referent'.

In notes:

x1 is redundant/unnecessary with x2 because the both satisfy property x3 (ka) under conditions / because of reason x4 (nu/du'u)