[{"Bold_text": "noun", "List Items": ["Pathology, Physiology.a hardened or thickened part of the skin; a callosity.a new growth of osseous matter at the ends of a fractured bone, serving to unite them.", "a hardened or thickened part of the skin; a callosity.", "a new growth of osseous matter at the ends of a fractured bone, serving to unite them.", "Also Botany.the tissue that forms over the wounds of plants, protecting the inner tissues and causing healing.a deposit on the perforated area of a sieve tube.(in grasses) a tough swelling at the base of a lemma or palea.", "the tissue that forms over the wounds of plants, protecting the inner tissues and causing healing.", "a deposit on the perforated area of a sieve tube.", "(in grasses) a tough swelling at the base of a lemma or palea."]}, {"Bold_text": "verb (used without object)", "List Items": ["to form a callus."]}, {"Bold_text": "verb (used with object)", "List Items": ["to produce a callus or calluses on:Heavy work callused his hands."]}]