deàrna

the palm of the hand, Irish déarna, Early Irish derna; cf. Greek $$Gdw$$nron, palm, handbreadth, $$Gdáris, the distance between the thumb and little finger, a span (Hes.), $$Gdarei$$`r, the distance between the big and little fingers (Hes.). It is further referred to the Indo-European root der, split, open (Fick, Prellwitz).