कृ + उ + नः
कृ धातु करणमेव
उ वैदिके शब्दार्थेति "च"
नः अस्मान्/अस्मभ्यम्/अस्माकम्
k.r means to do
u means "and" in vedic
naH means to us/for us/of us
So karuNa as pity/empathy describes perfectly the experience: there is on the one hand our action karma, that is one bhuuta being manifest in and as action *and* there is something done *to us* (the resonance of how it feels, empathic), *for us* something done (the enaction of dharma as a stabilizing influence and one which reduces suffering by taking the largest posible view), and *of us* something happens (we feel pity because of our openness to feel).