Sanskrit karkaṡa (28)
According to Monier-Williams’ A Sanskrit-English Dictionary, Sanskrit word karkaṡa denotes “hard, firm, rough, and harsh.” It traces its origin to the Tamil root kaṭu (strength), and due to the ṭ > r phonetic change, kaṭu (strength) transforms into karkaṡa in Sanskrit (kaṭu (strength) > kar > karkaṡa). The following words, related to Sanskrit karkaṡa, also originate from Tamil kaṭu (strength).
khára, “hard, harsh, rough.” khára-kāshṭhikā, “having hard wood.” khára-komala, “bracing yet mild.” khára-tvac, “having a rough bark.” khára-daṇḍa, “rough-stemmed.” khára-dhāra, “having a harsh edge or one full of notches.” khára-pātra, “an iron pot.” khára-pādâḍhya, “the elephant or wood apple.” khára-yashṭikā, “rough-stemmed.” khára-roman, “having rough hair.” khára-ṡabda, “harsh-voiced.” khára-soni, “an iron vessel.” khára-solla and khára-skandha, “having a rough stem.” kharâlika, “an iron arrow.” karkaṭa, “a crab; the sign Cancer.” karkaṭa-ṡriṅga, “the claw of a crab, gall-nut.” karkaṭâkhyā, “gall-nut.” karkaṭâsthi, “the shell or crust of a crab.” karkaṭaka, “a crab; the sign Cancer.” karkaṭakâtshi, “the shell or crust of a crab.” karki, “the sign Cancer.” karkara, “hard, firm; a bone; a hammer.” karká, “a crab.” karkareṭa, “the hand curved like a claw for the purpose of grasping anything.” karkaṡa-tva, “hardness; harshness, rough manners.” kārkaṡya, “roughness, hardness; rough labour; firmness, sternness.”