Hmmm. I had been told, long ago, that illiterate Westerners (mostly Christian, of course) would sign documents with an “X”, and kissed it, and preferably had it witnessed. I was told that it was the sign of the cross. Could it have been the Greek chi, instead, or did it, in the way of simple shapes and signs, tangle several roots together?
“Cross my heart and hope to die.” (Sounds like swearing on a holy symbol.)
Is it really lying if I cross my fingers behind my back? (Not for us kids, it wasn’t!)
XXXOOO (kisses and hugs)
I don’t think that all the uses of an “X” shape relate to the Greek Chi – it was used even earlier in the Ancient Near East, for instance, but in that period it would have been a Tau for those using the pre-exilic Hebrew alphabet (i.e. before Hebrew started being written using the Aramaic script).